new to birth control still haven't got my period

I started my second pack of birth control yesturday. I was supposed to get my period when I take the white pills there's 2 while pills that and two pink ones that have basically nothin in them. I just took the first blue one of the pack and still no period?! Should I be worried? I've had unprotected sex multiple times but my doctor said it would be okay to after a week which I waited for but I'm just really nervous...