One of the primary fertility signs is your basal body temperature, or BBT for short. Your BBT is the temperature of your body at your most rested state. Meaning the minute you wake up in the morning, before you get out of bed or move around at all, and after at least three hours of sleep. Your BBT is gone once you start to move around, which is why it is important to take your temperature immediately after you wake up and before you even get out of bed. In the first half of your cycle, the pre-ovulatory phase, your BBT will be low, usually around 97.3 to 97.8 F 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. Your temperature will stay high until you get your period. If you get pregnant at ovulation, your BBT would remain high throughout your pregnancy.
To learn more, tune into Kindara co-founder Kati Bicknell discussing the importance of temperature and fertility charting.
(P.S. Want a highly accurate basal thermometer that's fast, fits comfortably in your mouth, and doesn't beep? Try Wink, a bluetooth basal thermometer that automatically syncs your temperatures and the time your temperature was taken to the Kindara app.)