I need everybody's help!!!

Ok so I was supposed to start my period today November 16th. However I had some pinkish brown discharge on Wednesday which turned into bleeding on Thursday making me think I had started my period which lasts 4-5 days. However midday on Friday I was back to the pinkish brown discharge and that was it. I had unprotected sex the Monday before last which was either the 3rd or 4th. Could I be pregnant?