Period???

So I don’t know if this is something that happens to everyone but here goes, this morning I woke up with cramping in my stomach. I went to the bathroom and had diarrhea. When I wiped there was a good amount of blood in the toilet like I started my period. Here’s the problem.. I put in a tampon and went on with my day.. change the tampon and no blood. Completely clean. Backstory: I am trying to get pregnant and was supposed to start my period yesterday and I did have unprotected sex multiple times while I was ovulation but I have no symptoms of pregnancy.