Just curious

I suppose to come on my period on the 13. I been having mild cramps for a week now, but no period, yesterday I wiped very light pink blood was on the tissue, strange I know, I just got done having sex, so I went to restroom right after, there is no blood in the toliet, but very light pink blood on the tissue. Could this be a uti? I know I shouldn't be asking questions like this, but I don't have it figured out yet.