@talj You can start taking birth control pills on any day. Just take the first pill in the pack and one pill per day, in order.
Plan B works by delaying ovulation. Irregular bleeding and late periods are both common side effects.
@xmysticgohanx The pill thins the lining of the uterus, so it’s possible to have minimal or even no bleeding while taking it. A pregnancy test is most accurate 3 weeks after sex, regardless of bleeding.
@jessie101 If you’re worried about it you can skip the placebos and or use a barrier method until you’ve taken the 8th active pill in the next pack. But 4 hours is still considered on time for combination pills.