Emergency contraception is a remedial contraceptive method used by women to prevent unwanted pregnancy during unprotected sex, or within 72 hours after contraceptive failure or special circumstances of sexual intercourse. The common method is the oral emergency contraceptive pill. Generally, about a week after taking the emergency contraceptive pill, there will be withdrawal bleeding, indicating the success of contraception. However, the absence of withdrawal bleeding after taking the pill does not indicate contraceptive failure. If a woman does not have withdrawal bleeding, the pill is considered successful if she has a normal menstrual flow. The emergency contraceptive pill is easy to buy and easy to take orally, generally as the preferred way to avoid unplanned pregnancy, but if not done properly, there is a certain risk of pregnancy, so you need to pay attention to the following matters: 1. Correctly grasp the time to take the pill: generally after unprotected sex, you should take the emergency contraceptive pill within 72 hours, and then take one after 12 hours, the earlier you take it, the better. It is recommended to try to choose to take it after meals or before bedtime to reduce nausea, vomiting and other adverse reactions. If vomiting occurs within 2h after taking the pill, you should immediately take the same dose of emergency contraceptive pills, while taking antiemetic drugs to ensure the success of emergency contraception; 2. Avoid repeated long-term use: emergency contraceptive pills are only effective for one unprotected sex, and the drug hormone dose, side effects are also large, it is recommended to prohibit taking 2 times a month, 2-3 times within a year; 3. Avoid unprotected sex: oral After taking the emergency contraceptive pill, unprotected sex should be avoided during this menstrual cycle. If you have sexual intercourse, you should take condom and other conventional methods for contraception. If your period is delayed for 10 days and you have not had a period or there is abnormal bleeding, go to the hospital to check if there is a contraceptive failure or the possibility of ectopic pregnancy.