There are more types of contraceptives, such as short-acting oral contraceptives, long-acting oral contraceptives, emergency contraceptives, etc. There are differences in the time of menstruation after taking different types of contraceptives. The drugs should be used under the guidance of a doctor. Usually, after stopping short-acting oral contraceptives, menstruation may occur in 2-4 days; after taking long-acting contraceptives, menstruation may occur in 3-5 days; after taking emergency contraceptives, menstruation may be delayed for 7-10 days. 1. Short-acting oral contraceptive pills: Usually need to be taken for about 21~22 days, after taking the pills, menstruation may occur in about 2~4 days; if menstruation is delayed for one week after stopping the pills, the next phase of the medication should be taken in time. 2. Long-acting oral contraceptive pills: These pills are taken once a month, and withdrawal bleeding may occur 3 to 5 days after taking them. 3. Emergency contraceptive pills: these pills are mostly taken temporarily, within 72 hours after intercourse. After taking emergency contraceptive pills, the menstrual cycle may be disturbed, which may cause 7~10 days of delayed menstruation. When taking the pill for contraception, you should pay attention to the menstrual cycle after stopping the pill, and if there is any disturbance in the menstrual cycle, you need to go to the hospital in time for examination, to clarify the cause of the disease, and to carry out the treatment as soon as possible.