Discharge...Please help

So me and my boyfriend have been together for almost 3 years. I have recently been diagnosed with bipolarII disorder and the meds i'm on have left me with a very low sex drive so me and him do not have sex very often. But when we do it's always unprotected sex and I always have a bad smelling discharge like a day or two after.

We have a monogamous relationship and I get pap smears regularly I always come out clean and clear, this problem has been going on for a while so I have even asked him to go get checked out a few times and he is always clear too. I still feel that the discharge has someting to do with him because I never have this problem until after sex. I don't want to douche because I know that it's not a good thing to do. I am just wondering are any other women experiencing this and if so do you know why and is there anything I can do about it besides douching?