Before menstruation took birth control pills menstruation is very likely to be delayed for a few days, because taking birth control pills will lead to menstrual disorders, but this is still due to the individual’s physique, the impact will be different. The main ingredient of birth control pills is estrogen and progesterone, oral contraceptives will interfere with the normal level of hormones in the body. Short-acting contraceptives have a high dose of hormones and side effects. In addition to the side effects of menstrual disorders, irregular vaginal bleeding, early and delayed menstruation, nausea, vomiting, generally do not need special treatment, but if the menstrual period is prolonged for more than a week need to be excluded from pregnancy. If you experience delayed menstruation after taking birth control pills, don’t be anxious and observe the situation for a week or more.