Anyone bleed again days after your period ended is this spotting? Could I be pregnant?

Jess

Period started September 29 and by October 4th barely bled at all. I had sex on the 4th and 5th this weekend and I didn’t use a condom. Today I saw a pinkish spot on the toilet paper after I wiped this afternoon 3 days after my period was gone. Now I’m spotting a bit more still not bright as period blood. So strange why is this happening? Could it be implantation bleeding? I’m so confused.