Period late

My period is 9 days late! I started having cramps last night so I was thinking maybe my period will just be late because, I also took a pregnancy test and it came up negative. Should I take another pregnancy test? The last time I had sex it was unprotected and during my last period. But! I tried to use several birth control pills at once as early contraceptive (stupid idea i know, u dont have to tell me haha) is it possible that in doing so, I messed my cycle up?