Not having a period after taking birth control pills may be due to pregnancy or endocrine disorders. 1. Pregnancy: The lack of successful contraception after taking the pill may lead to unwanted pregnancy, and menstruation will no longer occur after pregnancy. You can take a urine HCG test with a pregnancy test one week after your period is delayed to rule out the possibility of pregnancy. 2. Endocrine disorders: long-acting oral contraceptives contain a large number of progestin components, more side effects, such as early pregnancy reactions, menstrual disorders, etc., which may lead to menstruation after taking the pill. Long-acting contraceptives generally have fewer side effects and only a few women experience amenorrhea after taking the pill. If menstruation still does not occur after stopping the pill, after ruling out pregnancy, stopping the pill for 7 days can continue to take the pill, if the continuous menopause for 3 months, the pill needs to be stopped for observation. When the contraceptive pill does not come to menstruation, you should go to the hospital in time to exclude pregnancy, according to the doctor’s advice and guidance to adjust the medication.