Yutin does not cause the occurrence of delayed menstruation, and if there is a delay in menstruation, it usually does not exceed 7 days. If there is a delay in menstruation for more than 7 days, you need to go to the hospital as soon as possible to have your blood HCG level checked to find out if the contraception has failed and there is a possibility of an unwanted pregnancy. For most patients, taking Yutin is within 72 hours of unprotected sex, and the earlier you take Yutin, the higher the success rate of contraception. After taking Yutin, most of them will cause menstrual changes, mostly in the form of early menstruation, because Yutin is a highly effective progestin, and after acting on the endometrium, there will be a withdrawal bleeding. If the patient experiences the above, there is no need to worry and stress too much, but need to take rest and observe the vaginal bleeding.