Implantation bleeding

Can you have implantation bleeding 3 days after sex? I’m on the nexplanon Implant and we use condom and my boyfriend pulls out before finishing. I check the condoms afterwards and they are never leaking. I’ve only had the implant for about two months and I skipped my period the first month after getting it and haven’t had any spotting until now. So I’m not sure if this is just spotting or if it could be implantation