Period on birth control help!!!!

I have been on birth control for to months and they said there could be some spotting but it happened one week before my period came. And I usually have a crime scene level flow, but this was like medium to light flow and it lasted like for four days. I am supposed to be on my period now but it really hasn’t came yet. I have been having like a brown discharge some days and then a very light blood other days. I did call my OBGYN when the sitting was happening to make sure everything was all right but she also said I would have my period like normal. I’m a little worried that for some reason I may be pregnant or something. Please help.