Ovulation usually occurs on the day of ovulation, i.e. within 24 hours, but ovulation is a period of time during which ovulation is possible. In a normal menstrual cycle, it takes about 2 weeks for the follicles to develop and mature, and ovulation occurs when the body’s hormone levels reach a certain peak, so ovulation is just an action that occurs over a period of time, and doesn’t need to be as long as a day or several days. Although the length of the follicular development period is variable, the ovulation period is relatively stable. If the menstrual cycle is 28-30 days long, ovulation usually occurs about 14 days before the next menstrual period, and the day of ovulation is called ovulation day. A woman will have 15-20 follicles growing and developing each month, but usually only one follicle can mature and expel an egg, and occasionally two eggs can be ovulated, with the two ovaries taking turns to ovulate. Proper intercourse during ovulation can increase the chances of conception. Ovulation of women, the body resistance will decline, this time women should pay attention to keep the vulva clean, wash with warm water every day, change cotton panties, to prevent infection.