fishy smell ONLY after he cums in me

it’s been ongoing, never use a condom (we’re married) & because I have the implant (arm). EVERY time we have p in v sex & he ejaculates in me, I have this fishy smell that lasts about 2 days. I shower daily & don’t use scented soaps. I don’t get itchy, no burning while peeing or anything, just smells really fishy. I’m going to call my dr office tomorrow & hopefully get an answer but could it be BV ? Or just my PH going out of wack because of his semen ?