Taking birth control pills may cause delayed menstruation. Birth control pills contain hormonal ingredients such as progesterone, which may lead to delayed menstruation or even amenorrhea, low menstrual flow, and heavy menstrual flow. Most delayed periods caused by oral contraceptives are nothing to be too worried about and do not require special treatment. If your period is delayed for more than a week, you can take an early pregnancy test to rule out whether the contraceptive pill has failed and caused pregnancy. However, the duration of delayed menstruation varies from person to person, with some delaying for a shorter period of time and some delaying for a longer period of time. There is no need to worry too much about delayed menstruation for less than twelve days, but if it is delayed for a longer period of time, then you need to consider a variety of reasons. In conclusion, do not take the pill for a long period of time unless it is an emergency. It is very common for the pill to cause menstrual disorders, and it may also cause changes in your menstrual cycle.