Implantation Bleeding?

So i’ve been sexually active only on birth control and he finishes inside me every time. starting yesterday i’ve had thin, PINK spotting where my periods are usually heavy and dark. i was supposed to get my period this week but skipped it with my birth control pill due to a vacation. can i take a pregnancy test while i’m still bleeding to confirm if this is implantation or just breakthrough bleeding? does this sound like implantation bleeding to anyone else?