If your period started on Thursday you start taking the pill on Sunday how long does it take before your protected against getting pregnant. also what day are you likely to get your withdrawal bleed?

You are protected from pregnancy once you have taken 7 pills in 7 days.

The withdrawal bleeding will depend on how your body reacts to the BCP. Some women have no bleeding, others spot continually for their first couple months of taking The Pill, others will have a few days of bleeding when they start taking the inactive pills in their packet.