Is it from stopping birth control or implantation bleeding?

Hey guys I had my period on July 8th it ended on the 13 and then on the 14th I stopped taking my birth control since I ran out and then on the 17th my boyfriend and I had unprotected sex and on Saturday and Sunday I had spotting and I’m not sure if it was implantation bleeding or not I don’t know if implantation bleeding happens that fast or not so if anyone could please let me know it would be very appreciated thank you!