Bleed after sex

Ive been having slight bleeding sometimes after sex. It doesn't happen all the time but last night I wiped and it was a little blood with some stinging. I'm thinking it is a cut that keeps reopening whenever we do it then the stinging relieves and it's ok. I don't have an OBGYN yet becaue my parents dint know I have sex and they can see it when I give them my insurance. Does this sound bad enough to checknwith a doc or no?