This situation is generally normal, this is due to the emergency contraceptive pills contain large doses of progesterone, after taking the drug, after a week of sudden stopping the drug will lead to the endometrium to lose the hormone support and shedding bleeding, bleeding is generally less than the amount of menstruation, and also a relatively short period of time, the average person 2-3 days will be clean. This is caused by the incompleteness of the uterine lining due to the withdrawal bleeding of the drug, you can continue to observe. In general, menstruation will come normally at the same time as before. However, if the amount of bleeding is heavy, similar to the usual amount of menstruation, you can treat it as the onset of menstruation and continue to observe the following menstruation.