Charting the Data
You can chart your temperature at any point. Once you have taken your temperature, you need to write it down (if you are not using a digital thermometer with a memory). You can save the actual charting for later in the day if you desire. It does not matter at what point you actually look at your chart.
As you can see from the sample chart, you will amass a lot of data very quickly. During the first part of your cycle, you will have lower temperatures than during the latter part of your cycle. To identify ovulation, you should look for at least a .4 degree rise over your average basal body temperature over the course of a couple of days. You may also notice a drop in temperature right before ovulation occurs.
Temperature Increases
This higher temperature should be the highest temperature over the previous days. Occasionally, illness or an inaccurate temperature will get in your chart for a variety of reasons. You will learn how to pinpoint these more easily the longer you chart.
When a temperature shift occurs and stays high for three consecutive days, you can assume you are ovulating. You have gone from the follicular phase into the next phase of your chart — the luteal phase.
Typically, the luteal phase lasts for the rest of your cycle. If you do not become pregnant, you will see a shift in your basal body temperatures back down to the averages found during the follicular phase as you once again begin your menstrual flow. If you become pregnant, your basal body temperatures tend to stay higher and above the temperatures you had earlier in the cycle. This is one way to tell if you are pregnant.
Please include any of the following as it pertains to your cycle: B=Bleeding/Spotting, S=Intercourse, M=Mucous noted, C=Position and condition of cervix noted, OPK=Ovulation Prediction Kit, MED=medications you are using, SUP=supplements you are using.
Basal body temperature chart
Drawing a Cover Line
Your cover line is the distinct line you draw through your charts to indicate a biphasic or two-phase cycle. It is used to help you find your ovulatory days and recognize if there is a pattern from cycle to cycle. It also helps to distinguish the follicular phase from the luteal phase. Some women may also note a triphasic chart — temperature peaks for preovulation, postovulation, and secondary postovulation — which is fine.
The cover line is usually fairly easy to draw. After you have taken your temperature for ten days, draw a line over the top of the highest normal temperature during this period. Do not include days of fever or other atypical temperature spikes. Once you have had a rise in temperature, draw a vertical line just before your rise in temperature.
When drawing your cover line be sure to exclude temperatures from your menstrual phase. The temperatures taken during this phase of your cycle are typically higher than those of your regular cycle and may throw you off.
Your cover line is a helpful tool not only for you, but for your practitioner as well. By using the concept of a cover line you can begin to make educated guesses about the subsequent cycles and identify potential problems with your cycles. This can also aid you in your cycle as you plan for ovulation.
As you start to chart your basal body temperatures you may be very excited. Some people even become obsessed with the numbers. They can be very interesting to look at, and it can be fun to try to decipher the information. Having your husband or partner help you with the plotting of information is a great way to help him get involved with tracking the optimum times for conception.
