Julie is a morning after emergency contraception 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 and won't impact an existing pregnancy. And, it doesn't affect your ability to get pregnant in the future.