So I just picked up my birth control and I have to start it the Sunday after my period ends. I know there is a period of time you have to wait for it to regulate your period and you will be fine. But once I'm well into it, if I have unprotected sex I will be safe right? I'm just asking for confirmation. I've heard a lot of stories when someone is on birth control and they get pregnant, one of them being my mom. It's supposed to keep you safe, but it's not 100% right? My pill is Cryselle and I'm 17.