After taking birth control pills will not affect menstruation, which usually comes normally, but some people will have early or delayed menstruation for no more than 1 week after taking birth control good. If your period is delayed for 10 days after taking the pill, you must go to a regular hospital for an examination to rule out the possibility of pregnancy. Because the contraceptive success rate of the pill is not 100%, if your period is delayed after using the pill, it is also possible that you are pregnant and it is recommended to check the blood HCG to rule out the possibility of pregnancy. If the abnormal menstruation is caused by the pill, it is recommended to check the thickness of the endometrium by ultrasound. If the endometrium has reached the thickness before the menstruation, you can continue to wait for the menstruation to come. If the period still does not come and the endometrium is thin, you need to see a doctor and treat according to the doctor’s recommendation.