Could I be pregnant

I had unprotected sex on my period but also used pullout. I also am on birthxknfrol and have been for almost 2 years I take it fairly regularly with a few mistakes with my busy schedule. I'm just stressed because I started spotting today and it's been about 4 days since I've been off my period. Could it be me having sex and also my constant use of tampons or could I be spotting