So about a week ago my partner and I were having sex but the condom slipped off and he finished inside. At this point I had been on a combination pill for nine days and had been experiencing some spotting. I talked to a pharmacist about what I should do and she told me I should still take a plan b which I did the same day. For about a week the spotting was gone, but I woke up this morning to some spotting yet again. My period is supposed to start in 12 days but the bc I'm using is actually supposed to stop my period from happening. Should I be concerned about pregnancy or is it just my birth control doing its thing?