Emergency contraceptive pill is taken within 72 hours after intercourse, the earlier the time of taking the pill, the better the effect, the general contraceptive rate of emergency contraceptive pills can reach more than 98%, so as long as the emergency contraceptive pills are taken in accordance with the prescribed method, whether in the safe period, or in the fertile period, the contraceptive rate can reach more than 98%. However, emergency contraceptive pills can easily lead to menstrual disorders, early menstruation, delayed menstruation or withdrawal bleeding after taking the pill, so emergency contraceptive pills are not a regular contraceptive method, it is generally recommended that no more than three times a year, too many times to take emergency contraceptive pills, easy to cause menstrual disorders, and even affect the ovarian function.