Progesterone is highest in the female body 7-8 days after ovulation. Progesterone in the female body is very low because the follicles do not secrete progesterone during ovulation. By the time of preovulation, a small amount of progesterone is secreted at this time due to the action of luteinizing hormone, and the progesterone secreted by the corpus luteum gradually increases after ovulation. About a week after ovulation, the corpus luteum in a woman’s body starts to mature and progesterone secretion reaches its peak, and then it gradually decreases to the level of the follicular phase by the time of menstruation. Therefore, it can also determine whether a woman is pregnant or not. If the progesterone secretion is still high after pregnancy until the menstrual period, there will be no menstrual period, which can also determine whether a woman is pregnant.