Herpes or just rough sex?

Ever since I met my husband, every once in awhile, usually after "difficulty" achieving orgasm during sex, I will wake up the next day with an itchy spot next to my urethra. It usually turns into an itchy/painful spot the next day. It is always flat. Never dips in the skin or raises above the skin. Once or twice I notice a white/pink film over it, but it never scabbed, it just faded. Most of the time it looks like some sort of skin abraision. It usually takes about a week to heal. The dr has taken skin swabs twice of this and both times it came back negative. My husband has had a blood test since we married and he came back negative too. I am wondering what this is that keeps happening to me though? When we first met it happened more frequently now it only happens once a year or less. But it concerns me. What do you think?