Well I was supposed to start my period around the around the 16th, but my periods are never really on an exact cycle. They either go under or over by a few days.

Well on the 15th my bf and I had sex and when we were done, he came back and asked me if I had started my period because there was blood on him. I went to the bathroom and there was blood. I have never bled during sex, and the sex was normal and nothing hurt. I went to the bathroom and few hours later and there was still just a tad bit of blood. The blood was not from a lubrication issue.

After that, nothing else happened. I didn't continue with my period or anything. My bf and I have unprotected sex, so im wondering if that was what they maybe call implantation bleeding? The bleeding did not come from the sex, thats just when we discovered it because I hadn't been to the bathroom in a while.

What could it be?