What is basal body temperature?

Early morning temp: The basal body temperature is the temperature your body is at when you first wake up, before you get moving for the day. We use it to check for when your body releases an egg. It can only be measured with a special thermometer which reads temperature at a more accurate scale.

Basal Body Temp, BBT: Bbt, basal body temperature, is a woman's temperature at baseline, first thing in the morning, before arising out of bed. Bbt tends to be low in the first two weeks of the menstrual cycle, then rises just before ovulation, by about half a degree.