How To Cure Unpleasant Vaginal Odour After Having Sex ?

Hello. I am 6 weeks pregnant and have had an issue of a fishy smell for days after my husband ejaculates inside of me. It takes days for the smell to go away and comes back as soon as we have intercourse again. This was happening for a few months before we got pregnant and I thought maybe it was a ph issue so I started taking an herb to help keep my ph at a normal level but it is still happening now and I don t know what other things I could try to elimatw this major hygiene issue I am quite embarrassed about.