You can ovulate about 7 days after your period clears. For women of childbearing age with regular menstruation and a menstrual cycle of 28 days, the day of menstruation is the first day of the menstrual cycle and the 14th day is the day of ovulation, which means that most women have menstrual periods of 5-7 days and ovulation occurs about 7-9 days after menstruation. Since the egg survives for 12-24 hours and the sperm survives for 72 hours after entering the body, the three days before and after ovulation have a chance of conception, so this period is called the ovulation period. Women who need to prepare for pregnancy can use the ovulation period to have intercourse in order to increase their chances of conception. In addition, it is not accurate to use the end of the menstrual period to predict the day of ovulation, but a more accurate algorithm is the 14th day of the menstrual period. Also, women with irregular menstrual cycles and ovulation disorders should not use this method to calculate.