Since emergency contraceptive pills are highly effective progestins, clinically they cause abnormal thickening of the uterine lining, preventing the fertilized egg from implanting and achieving contraception. In addition, emergency contraceptive pills can also inhibit ovarian ovulation to achieve the purpose of contraception. Therefore, whether it is 1 month after the abortion, or at other time period took emergency contraceptive pills, in the clinical situation may lead to menstrual disorders. This is mainly due to the suppression of ovulation, which disrupts the ovaries’ cyclical secretion of estrogen and progesterone, and the natural pattern is disrupted, leading to menstrual disorders. Since progesterone causes the uterine lining to thicken abnormally, it can also lead to cases of withdrawal bleeding.