Hi - I just filled a prescription for Aviane, and everything I read says that I should start taking it the Sunday after the beginning of my period (which started this past Tuesday). (Those are the instructions for women who haven't been on birth control before, which describes me.) What is so special about Sunday? It seems like it's important to start taking it during or close to when I've gotten my period because that's when hormone levels are low, but can I start taking it today (Monday) and still have it be effective? Or do I have to wait until I get my period next to start it now that I missed taking it on Sunday?

Thanks in advance for your advice.