In Part One of this series we went over cervical mucus and how to determine when we are ovulating. Today we are covering taking your basal body temperature to determine where you are in your cycle and if you have ovulated, otherwise referred to as fertility charting.
Article by: Marie Zenack
Basal Body Temperature
If you are not sure you are ovulating, you can take your temperature. The body’s resting temperature increases four-tenths of a degree Fahrenheit or two-tenths of a degree Centigrade under the influence of progesterone at ovulation. Observing this sign involves taking your temperature at the same time each morning before rising. (This is not as hard as it sounds. It takes less than two minutes and you can go back to sleep if you want.)
To observe your temperature rise, buy a BD brand or ibasal digital basal thermometer. This brand will give you a consistent and accurate reading. Other high-quality brands of digital basal thermometers are also probably accurate, but have not been tested for fertility awareness. Make sure the battery is good. (You can replace it.) An ordinary clinical thermometer is not accurate enough for fertility awareness, nor is the “ear thermometer” (tympanic thermometer).
Take your temperature every day immediately upon waking, before 7:30 a.m. The body’s rhythms (circadian rhythms) fluctuate over a 24-hour period. Your temperature is lowest in the early morning and highest in the afternoon. Fluctuations are greater after 7:30 a.m. If you go to bed before midnight and wake up before 7:30 a.m., you will get the clearest temperature readings.
If it is not convenient to take your temperature immediately upon waking, you may take it during light morning activity. For example, if you need to go to the bathroom, you may take your temperature while getting up and using the toilet. But be consistent about the circumstances under which you take your temperature. If you take it during light morning activity, take it that way every morning. Don’t take it sometimes before getting up and at other times during light morning activity. If you have sexual relations, take your temperature before.
Many women find that the digital thermometers require such a short time to use that it is easy to take their temperature before getting up. Take your temperature by mouth. Under arm and ear temperatures are not accurate enough for family planning purposes. The thermometer will beep softly several times before beginning to beep slightly louder and repeatedly. Keep the thermometer under your tongue until the louder, repeated beeps begin. You can read and chart your temperature when it is convenient. Your thermometer has a recall button that allows you to read the last temperature taken. Be sure to wash your thermometer after each use.
About The Author
Marie Zenack is a teacher of fertility awareness and a facilitator of women’s rites of passage at Earth Wisdom, Natural Family Planning and Fertility Awareness.