Taking Charge of Your Fertility

by Toni Weschler

  You may have already noticed that you will only be able to determine the Peak Day in retrospect, on the following day. This is because you can recognize it only after your cervical fluid and vaginal sensation have already dried up. This concept should become intuitive fairly quickly. Also be aware that the Peak Day is not necessarily the day of the greatest quantity of cervical fluid. In fact, the “longest eggwhite stretch” or greatest amount could occur a day or two before, as seen in Julia’s chart.

  1. Your Peak Day is the last day of either:

  •eggwhite, or

  •lubricative vaginal sensation

  This means that if your last day of eggwhite is on a Monday, but you still have one more day of lubricative vaginal sensation (or spotting) on Tuesday, your Peak Day is Tuesday. Your Peak Day is always determined in retrospect the following day.

  2. If you don’t have eggwhite, you would count the last day of the wettest-quality cervical fluid you do have, which may be creamy or smooth, for example. (Of course, once again, if your last day of creamy is on a Monday, but your last day of wet vaginal sensation is on a Tuesday, your Peak Day would be Tuesday.)

  3. Some women will occasionally have a day or two of some other type of cervical fluid after their last day of eggwhite. The Peak Day is still the last day of eggwhite or lubricative vaginal sensation.

  4. One of the hallmarks of the Peak Day, and what makes it fairly easy to identify, is the abrupt and dramatic drying following it, caused by the beginning of the rise in progesterone.

  5. Once you have identified the Peak Day, you should write “PK” in the Peak Day row of your chart. The charts below show the most common cervical fluid patterns and how their corresponding Peak Days would be recorded.

  ANOVULATORY CYCLES AND THE PEAK DAY

  One of the reasons I encourage you to chart both your cervical fluid and temps is that if you observe only your cervical fluid, you could be misled and believe that you are ovulating when you are not. This is because your body may make attempts to ovulate by increasing its levels of estrogen in a seemingly consistent pattern, but if the estrogen doesn’t pass over the hormonal threshold, the egg won’t be released. By charting both, you will be able to observe the increase in fertile cervical fluid that indicates approaching ovulation, while the lack of a thermal shift can clarify that you have not, in fact, ovulated yet.

  A trick to help you identify whether or not you are ovulating is to pay special attention to the concept of the Peak Day. If you do ovulate, the cervical fluid should dry up fairly abruptly, due to the release of progesterone. In situations where your body may be unsuccessfully attempting to ovulate (for example, in long cycles, while breastfeeding, or because of PCOS), you would typically observe a pattern of increasingly wet cervical fluid, but instead of fully drying up under the influence of progesterone, it would likely return in sporadic patches, or simply remain somewhat wet. (Further discussion of anovulation is in the following chapter.)

  Sheila’s chart. The classic cervical fluid pattern, with the last day of slippery eggwhite as the Peak Day. In this case, her Peak Day was Day 17.

  Julia’s chart. The same basic pattern of cervical fluid as Sheila’s chart above, except Julia still has a lubricative vaginal sensation (recorded as “lube”) the day after her last day of slippery eggwhite. Thus, her Peak Day was Day 18.

  Miriam’s chart. A cervical fluid pattern in which slippery eggwhite is never observed. Miriam’s Peak Day was therefore Day 13, the last day of wet, creamy cervical fluid.

  Ariana’s chart. A cervical fluid pattern in which a day of creamy follows the last day of slippery eggwhite. In this case, Ariana’s Peak Day was still considered Day 11, the last eggwhite day. Also note that because she ovulated early, this cycle is short, which is not surprising, because she didn’t have any dry days immediately following her period.

  Knowing how to accurately determine your Peak Day is crucial if you are to correctly follow the rules for both birth control and getting pregnant, so be sure to carefully internalize the guidelines and the sample charts above.

  WAKING TEMPERATURE

  The first time I heard that FAM involved taking a temperature every day, I thought, “You can’t be serious!” But 11,000 temps later, I lost sight of what the big deal was. In fact, it’s nice to have an excuse to snuggle a minute, warm and cuddly—rather than feeling the need to bolt out of bed the second the alarm goes off.

  Now, granted, in order to get an accurate reading, you probably don’t want to do 50 sit-ups before taking it. Nor, for that matter, should you jump up to grab your smartphone in the other room or even get up to urinate right after waking up, even if you downed two pints of lemonade the night before.

  But on the positive side, taking your temps will provide you with a wealth of information about your body that, when all is said and done, will probably take about a minute of your day. To fully appreciate what I am saying, let me list the benefits of taking your temperature every morning. You will be able to identify:

  •if you are ovulating

  •when it would be safe to have wonderfully natural intercourse without risk of an unplanned pregnancy

  •when you are no longer fertile, if you want to avoid a pregnancy, or when you are still fertile if you want to achieve one

  •when you will get your period

  •if there are potential problems in your cycle

  Taking Your Temperature

  1. Take your temp first thing upon awakening, before any other activity such as drinking, talking on the phone, or getting up to use the bathroom. Ideally, it should be taken throughout the cycle, including during menstruation. (If you prefer, you may restrict temperature taking to about one-third of the cycle, as discussed in Chapter 12 on “Shortcuts.” However, if you are using FAM for birth control, I would strongly discourage you from using shortcuts until you have charted at least several cycles.)

  2. You should take your temps about the same time every morning, give or take about an hour. However, you don’t need to be a slave to your thermometer. If you sleep in on the weekends, or for whatever reason take it earlier or later than usual, just be sure to note the time on your chart, because for some women, basal temps tend to creep up the later you take them. Still, many women find that if they get up to use the bathroom and take their temps while going, it doesn’t affect them. Or, if they immediately go back to bed, it won’t affect their temps if taken shortly after. (For how to handle the outlying temperature that may result, see the Rule of Thumb.)

  3. If using a digital thermometer, wait until it beeps, usually about a minute. If using a glass basal body thermometer, leave it in for five minutes, but shake it down the day before so that you won’t risk raising your temps.

  4. Take your temperature orally. If you find that you don’t get a clear pattern, you may want to take it vaginally. Either way, just be aware that it’s important to be consistent and always take it the same way throughout the cycle because vaginal temps tend to be higher than oral temps.

  5. Regardless, if using a digital thermometer and you still don’t get a clear thermal shift, you can try leaving it in for an extra minute or two, so long as you do so consistently.

  HOW SENSITIVE IS YOUR BODY TO WHEN YOU TAKE YOUR TEMPS?

  Some women can sleepwalk in the snow an hour before taking their temps, and it wouldn’t make a difference. Others are so sensitive to the slightest variation that just being woken by a car alarm a couple hours before getting up could disturb their temperature reading. Fortunately for most women, none of these variations will make much difference.

  Even for those of you who are more sensitive, you’re still likely to go to bed and wake up about the same time every morning, even if you don’t actually get out of bed at the same time. Of course, sometimes life gets in the way. For example, you may normally get at least three consecutive hours of sleep before taking your temp, but sometimes you have to pee so bad that you go first, or go back to bed and only get an hour of sleep before t
aking it. Or maybe you have a couple glasses of wine now and then the night before. In the end, if your temps seem all over the map, you might want to try an experiment.

  Record in one color the temps you take about the same time after about the same amount of sleep. But any time that you experience something different, record the aberration in another color, always noting the anomaly in the Miscellaneous row (e.g., wine last night, awoken by phone) or the Time Temp Taken row (5:30 a.m., instead of the usual 7 a.m.).

  If you notice a conspicuous difference, try to maintain as much consistency as possible, including recording your temp about the same time and getting at least three consecutive hours of sleep before doing so. And of course, don’t rely on any confusing cycles until you have established normal temperature charts. In the end, you’ll always have the handy Rule of Thumb to help you accurately interpret your charts.

  Charting Your Temperature

  1. You can record your temps at any time that day, but it’s usually more interesting to do so in the morning so that you can get immediate feedback about what’s happening in your body. If this isn’t practical, it doesn’t need to be done until the evening, since most digital and glass thermometers will remain accurate until read or shaken down. (Just be sure not to leave your thermometer roasting on a hot windowsill all day.)

  2. If the temperature falls between two numbers on a glass thermometer, always record the lowest temp.

  3. Record and connect the temps with a pen.

  4. Unusual events such as stress, illness, travel, or moving should be recorded in the Notes row of the chart and taken into consideration when interpreting the temperature pattern. And temps taken earlier or later than usual should be noted in the Time Temp Taken row.

  5. If your temps seem confusing or erratic, try taking them vaginally for at least a full cycle from period to period. You may be someone for whom vaginal temps are more accurate.

  6. If you think a temperature is outside the normal range, apply the Rule of Thumb and wait until the next day to draw the connecting line. Omit any aberrant temps by drawing a dotted line between the normal temps. Record possible reasons for their aberrations (see Catherine’s chart).

  A GUIDE TO THERMOMETERS

  Digital Thermometers

  For most women, the most convenient type of thermometer is a digital one. It usually requires only about a minute to register and typically beeps when it’s done. For charting purposes, it should have memory capable of storing the last temperature until you retrieve it at the time you record. Also, it’s imperative that it be accurate to within 1/10th degree Fahrenheit (for example, 97.4), but do not use thermometers that measure to within 1/100th of a degree (for example, 97.47), since the extra information is unnecessary and confusing. And be attentive to when you need to change the battery.

  You can rely on digital thermometers as long as they clearly show the midcycle thermal shift that signals the passing of ovulation. But if your temps seem confusing, if they do not show a clear pattern of pre- and postovulatory lows and highs, or do not correlate closely with your other fertility signs, try a different digital or switch to a glass basal body thermometer at the beginning of a new cycle.

  You should also be aware that there are several new digital thermometers that are specifically designed to sync with mobile apps, including one for the app that goes with this book. See tcoyf.com.

  Glass Basal Body Thermometers

  Glass thermometers are considered the most reliable thermometer for detecting your basal body temperature (BBT). However, they are rarely sold anymore, and do require a full five minutes to register an accurate reading. The thermometer packaging should specify that it’s a “basal body” thermometer as opposed to a “fever thermometer.” A glass basal body thermometer is easier to read than a glass fever type because the temps are shown in increments of 1/10th rather than 2/10ths degrees F. But BBT thermometers only register up to 100 degrees F., so if you have reason to think you are developing a fever, be sure to use a fever thermometer during those days.

  Ear or Forehead Thermometers

  Alas, these types of thermometers are still not considered reliable enough to be used for Fertility Awareness charting.

  Drawing the Coverline

  Ultimately, the reason you chart your temps is to determine when you ovulated in any given cycle. Remember that after ovulation, temps quickly rise above the range of lows that preceded it, forming a biphasic pattern on the chart. This thermal shift is often so obvious that you’ll be able to spot it simply by glancing at the chart. However, in order to interpret accurately, you’ll want to draw a coverline to help you differentiate between temps that are low (preovulatory) and high (postovulatory). Your evolving, wetter cervical fluid will be your sign to start paying attention to your temps, because it’s the first indication that you are getting closer to ovulation. The coverline is drawn as follows:*

  1.After your period ends and once you start noticing wet cervical fluid, begin watching for a temp that is higher than the cluster of six preceding temps.

  2.Identify the first day your temps rise at least two-tenths of a degree above the highest in the cluster of the preceding six temps.

  3.Look back and highlight the last six temps before the rise.

  4.Draw the coverline one-tenth above the highest of that cluster of 6 highlighted days preceding the rise as seen in Kate’s chart below. (It’s not unusual to have high temps during menses due to the residual effects of progesterone lingering from the last cycle. But they can be ignored when drawing the coverline.)

  Kate’s chart. A standard temperature pattern with coverline. Note that the first day that Kate noticed a temperature shift was Day 17, so she counted back six days and highlighted that cluster of temperatures. Then she drew her coverline on 97.7, which was 1/10th above the highest of the cluster, which was 97.6 on Day 14. This cycle length was 30 days.

  Outlying Temps and the Rule of Thumb

  If you have an occasional temperature that is unusually high due to reasons such as fever, a restless night’s sleep, alcohol consumption the night before, or taking it later than usual, you may cover the outlying temp with your thumb when you are determining your coverline. Circle the unusual temp as you would any other, but then draw dotted lines between the temps on either side, so that it doesn’t interfere with your ability to interpret your chart. You essentially ignore the abnormal temp during the 6-day count back when determining your coverline. However, if there are two outlying temps, count back an additional day.

  You should also be aware that in some women, temps rise a bit when they sleep in, but again, you should simply follow the guidelines above. See the Charting Temps During Special Circumstances box below for how to handle special circumstances, as well as the Fever section for how to deal with fevers.

  Catherine’s chart. Using the Rule of Thumb for aberrant temperatures. Note Catherine’s thumb covering her outlying temperature on Day 13 and that she drew a dotted line between the days on both sides of it. Also notice that Day 13 is not counted among the necessary 6 days to draw the coverline. This cycle length was 28 days.

  Types of Thermal Shift Patterns

  Catherine’s chart above shows a coverline drawn with a standard thermal shift pattern. The standard pattern clearly shows the range of low temps, followed by a distinct thermal shift of at least two-tenths of a degree, followed by a consistent range of high temps that remain until the end of that cycle. Standard patterns are the easiest to interpret, and thus drawing the coverline for them is a breeze.

  Most women tend to experience the same type of thermal shift patterns within their own cycles, although they may see variation now and then. While the standard shift is the most common, there are three other types that you may experience, all shown below.

  Talia’s chart. The slow-rise. Note how her temperature rises 1/10th of a degree at a time, starting with Day 17 as the first temperature higher than the cluster of the six before it. Also notice that with this parti
cular pattern, the coverline cannot be drawn using the standard instruction.

  Brooke’s chart. The stair-step rise. Note how her temperature rises in an initial spurt of about 3 days on Day 17 before rising further on Day 20.

  Kelly’s chart. The fall-back rise. Note how her temperature initially rises above the coverline on Day 17, but then falls back the next day before rising above again on Day 19.

  While the above patterns can be a bit confusing initially, they are easy to interpret once you are familiar with them. Appendix H give further explanation should you find that you have cycles that resemble them.

  CHARTING TEMPS DURING SPECIAL CIRCUMSTANCES

  Travel Across Time Zones and Daylight Saving Time

  Occasionally, you may experience a change in time zones, either when you travel or because of Daylight Saving Time. If you are someone whose body is sensitive to what time you take your temp, just be aware of the possibility that it may register higher or lower that day, since temps tend to rise later in the day. If you notice an aberration, ignore it by applying the Rule of Thumb. However, if you work for the airlines or have some other job that requires you to constantly travel across times zones, you may not be able to realistically chart your temps effectively, but you still can rely on your other fertility signs. (See Cervical Fluid Only Rules for how to maximize contraceptive effectiveness in such situations.)