Analysis: Hello, the emergency contraceptive pill drug contraception principle is to inhibit, delay ovulation, and adjust the state of the uterine lining forcing women to change the time of the next menstrual period, if it is in the first half of the menstrual cycle to take Yutin, the women's menstrual interference is greater, easy to vaginal bleeding; in the second half of the menstrual cycle to take Yutin on women's menstruation interference is smaller, advice: it is recommended to take emergency contraceptive pills! After having sex again, there is still a possibility of pregnancy. Because Yutin is only used after the last unprotected intercourse, it does not work for the next unprotected intercourse. Therefore, if you have sex again, you still need to use contraception. The incidence of irregular bleeding or menstrual changes is high, and overdose and frequent use of the drug can cause menstrual disorders , and should not be taken more than three times a year.