Julie is a morning after emergency contraceptive that helps prevent pregnancy before it starts when taken within 72 hours after unprotected sex. The sooner it's taken, the better it works. Julie works by temporarily delaying ovulation or the release of an egg from the ovary. No egg, no fertilization, no pregnancy. Julie will not work if you are already pregnant or ovulating. Julie won't impact an existing pregnancy and it doesn't affect your ability to get pregnant in the future.