Spotting after sex

So I am 4 days away from my period according to glow but I know I ovulated 2 days earlier so really my period is due in two days. I had sex with my bf last night and when we were done I noticed really light brown blood it wasn’t too much so I assumed the sex made my period come early but today the spotting stopped..what could be the cause of the spotting? I have no infections and anything to that sort. I also been cramping more than usual since maybe a week or a week and a half ago.