Help please! !!

Okkk I had my period about two weeks ago and the second week I did have unprotected sex with my ex and thinking it wouldn't do nothing. But I spotted yesterday just a lil bit and I put in a tampon and when I changed it it was mostly clean so yea i was shocked and then I put in another one then that one came out clean to and idk wat that means. Can anyone please help me out here and yes I'm regular with my lady time.