Carbamazepine can make Norgestrel + Ethinyl Estradiol + Ferrous Fumarate work less well as a contraceptive. It speeds up the way your body clears the hormones in the pill, so less of them stays in your blood. Because of this, the pill may not protect you from pregnancy as reliably as it should.
These medicines are often taken together with some care. Your doctor may change a dose, space them apart or check on you more often. Make sure your doctor and pharmacist know you take both.