Your temperature when you are fully at rest is called basal body temperature (BBT), and it will usually be biphasic, meaning lower before ovulation and higher after ovulation, in harmony with the luteinizing hormone (LH). To capture BBT, take your temperature before any other activity and after at least 4 hours of sleep. Temperatures must remain elevated for at least 3 days to confirm ovulation (1).
Your BBT rises once you start to move around, which is why it is important to take your temperature immediately after you wake up, and before getting out of bed. Temperature is helpful to confirm that you are ovulating and that you have a luteal phase that is able to support a pregnancy (2).
In the first half of your cycle, the pre-ovulatory phase, your BBT will be low, usually around 97.3F to 97.8F for most women. After ovulation (when you release an egg) your body will start producing the hormone progesterone. Progesterone will cause your BBT to rise, and your temperature each morning will be slightly higher (usually at least 0.3 degrees) than in the pre-ovulatory phase (3). Your temperature will stay high until you get your period. If you get pregnant at ovulation, your BBT would remain high throughout your pregnancy (4).
Read more about BBT on our Kindara Blog!
1) Weschler, T. (2015). Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health.
2) Mesen, T. B., & Young, S. L. (2015). Progesterone and the luteal phase: a requisite to reproduction. Obstetrics and Gynecology Clinics, 42(1), 135-151.
3) Barron, M. L., & Fehring, R. J. (2005). Basal body temperature assessment: is it useful to couples seeking pregnancy?. MCN: The American Journal of Maternal/Child Nursing, 30(5), 290-296.
4) Weschler, T. (2015). Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health.