Kim Yutin, also known as levonorgestrel tablets, is a kind of emergency contraceptive pill that is widely used in clinical practice. After taking this contraceptive pill, it will cause endometrial necrosis and shedding due to the effect of high dose of progesterone, and withdrawal bleeding will occur, and different patients will have different performance after taking the pill. Withdrawal bleeding usually occurs about 3-7 days after taking the pill. Some patients may have a small amount of spotting or no bleeding, and the bleeding symptoms are related to being in different periods of menstruation when taking the pill. If you take the pill during the first half of your period, you may not experience significant vaginal bleeding because your uterine lining is still thin; if you take the pill during the second half of your period, you will experience relatively heavy vaginal bleeding. Vaginal bleeding is a common phenomenon after taking the emergency contraceptive pill. If the amount of retreating bleeding is relatively high and basically equal to the usual amount of menstrual blood, the bleeding can be regarded as a menstrual flow, which also indicates the success of contraception.