Hi, disclaimer this might be a tad TMI but I got to get it out there and get some advice. For about 5 days now, I have had a strange smell coming from my vagina, no increase in discharge than normal just a weird smell, it smells like rotting semen. I can't see this being bacterial vaginosis as I've had no other symptoms. Myself and my boyfriend last had intercourse about a week ago during my fertile window and I have been ovulating whilst I have been having this odour. During last weeks intercourse he didn't ejaculate inside me either so I can't really put a reason to this semen smell. Just thought I'd try and get some advice on here before I take the next step to see a nurse 
Let me know if you get an answer. My gf and I have been together for 8 months and I've never thought she was cheating on me, and would never have imagined she'd allow another man to ejaculate inside her. Last weekend i went down on her and thought..... well she did smell like semen. Id love to hear another explaination and not have to confront her.