Maybe you can answer my question

Ok so on my 3rd day of ovulation, when I say 3rd day I mean I discharge a lot during the week of high chances of becoming pregnant. Anyways, so that day I had sex and after we finish I took a bath everything was fine down there, just clear discharge. In the morning I woke up with a dark discharge, I only wear a pantyliner and by the afternoon it was gone. Well today I'm 4 dpo and Ive being cramping since yesterday, my period is not due until July 1st. What is going on? should I see my ob/gym?