Small follicles usually develop on the second day of menstruation and mature and ovulate on the 14th to 15th day of menstruation. In women who have regular menstrual periods, follicles usually begin to develop after the end of the period, when they are in the initial development stage, and they mature and ovulate on about the 14th to 15th day of menstruation. It can also be projected that the 14 days before the onset of menstruation is the day of ovulation, and the 4 to 5 days before and after the day of ovulation are considered to be the ovulation period. If your menstrual cycle is irregular and the time of ovulation is not easy to predict, you can go to the hospital for ultrasound to detect ovulation or use ovulation test paper to detect it. It is recommended to have intercourse during the ovulation period to increase the probability of conception if you have fertility requirements. If you do not want to have children, you should take proper contraceptive measures to avoid unplanned pregnancy.