Does birth control cause bad cramps?

No - oral contraceptive pills usually decrease menstrual pain. The cramps we get during our periods are usually due to the uterus contracting in order to get rid of the endometrium (which is the bleeding we get). Oral contraceptive pills reduce these contractions and should therefore reduce the pain. If your cramps are getting worse, there may be some other reason for this and you should make an appointment with your doctor.