I had sex a few days ago and Im spotting blood. I should be Starting my period. Why is this?

You might be go to your regular doctor and ask.

You may have had implantation bleeding my period was due 8/17 i had 1 little spot on the 16th then no period took a test(a cheap dollar one from dollar general...no joke) it came back positive then i made a dr appointment and confirmed it....implantation bleeding may come with mild cramping