My period has been starting around on the 10th of each month, now this month it started on the 9th normally lasts 7 days. My doctor said they schedule these surgerys on the 2nd or 3rd week of your cycle.. Can someone explain this? I'm confused. So they scheduled me for September 28th, and my period should start around the 9th or 10th according to glow it's going to start on the 8th. Would I be better off changing my surgery to the 21st or keeping it for the 28th. What day would be considered my 2nd week of my cycle and my 3rd week? Please help so confused.