If you start birth control on the quick start method a week before your period is supposed to come will your period come when it normally does or not until the end of the first pill pack?

Starting use of Birth Control pills at any time can change when a period occures but there is no way to predict if it will for sure or by how much. A change is still possible even if you start on the last day of a period. After you've been on them for three months, you'll see how your bleeding pattern is likely to be.