Help! Please!

My boyfriend and I had sex on April 29. He used a condom and I am 100% sure he didn’t even ejaculate. I’m a super anxious person about becoming pregnant. I know there’s like no way, but I can’t help but worry. I’m concerned because I got what I thought was my period two days later. It was dark red, clotty, and a little brown but it looked like any normal period. I was happy at first because I thought it meant I for sure wasn’t pregnant. But then, after that day, it’s almost stopped. No blood comes out, it is only brown discharge, but that’s even rare. I haven’t experienced any nausea or anything out of the ordinary since we had sex, except for this weird “period” thing. I didn’t think much of it until I googled it and read about the whole “spotting after implantation” thing. I don’t think that’s what it is, because my period is known for being quite unusual and irregular, but I always scare myself. Can I get someone’s opinion please! It would help me so much.