Bacterial Vaginosis, Help!

So for some reason when me and my partner BD his Sperm will later cause me to develop bacterial Vaginosis. I don't get one when he pulls out!! So for some reason his sperm is causing this and we are TTC now so I do not want him to pull out. I've asked my doctor and she said feminine probiotics so I am going to try those and see if they work.. But if anyone else has the same problem or any insight please respond! I am tired of going to the doctors over and over. Please Help!