I started Yasmin birthcontrol on Day 1 of my period. I had been on Orthotricyclen before, but went off of it for a month before starting Yasmin. I had unprotected sex with my boyfriend for the first time on Day 1 of my period. What are the chances of getting pregnant? I thought that you didn't have to use a backup form if you started your pill on Day 1. Please help! Also, is my period supposed to start at the beginning of the inactive pills or at the end of them?