Aunt medically known as menstruation, after taking emergency contraceptive pills the time of menstruation is not absolute, may be a week early, or delayed a week, or may be normal, always follow the doctor’s instructions for the scientific use of medication. If a woman takes emergency contraceptive pills once in a while, there is no obvious adverse drug reaction, she will have her period in the normal menstrual cycle. However, if a woman takes emergency contraceptive pills repeatedly within a short period of time, the level of sex hormones in the body will change significantly, which may have a significant impact on menstruation. Some women may experience withdrawal bleeding about 3-7 days after taking the pill, which may be mistaken for the onset of menstruation; and some women may experience a delay in menstruation for 1-2 months without menstruation. It should be noted that the emergency contraceptive pill is best used within 72 hours of sex, the sooner you take it, the better the effect, but the emergency contraceptive pill can not achieve 100% contraceptive effect, and sometimes there is the possibility of failure, it is recommended that in the case of delayed menstruation, go to the hospital in a timely manner to check whether the pregnancy.