HELP.

I'm asking this again since EVERY question I ask no one ever helps me. If I'm starting birth control for the first time and I got my period today (Sat) do I start taking the first pill tomorrow (Sun) or wait til next Sun when my period is over? My doctor didn't give me any instructions. **EDIT - The packet says "Take your first pill on the first Sunday following the start of your period" sooo wouldn't that mean I take the pill tomorrow?