I was told to start the birth control the Sunday after your period started.
Like if you got your period Monday then this coming Sunday is when you would start.
Hello, well. I'd read the package insert. I think you can start it any time but it is good to start on a Sunday as then it avoids periods during the weekends. This is assuming you have the traditional four week pack that has three weeks of hormones and one week of sugar pills. So, you can start it any time but I'd wait until Sunday. Use back up birth control for a week (I'd do two to be safe) after you start the pills. good luck