BV- fishy

Does anyone else ever get bacterial vaginitis after their period or sex? I never had this issue until I hit my 30s and I'm in a long term relationship now, but it's embarrassing when you have a fishy scent sometimes. I've gone to the doctor and even the 3 day vaginal gel didn't work. She had to prescribe me the pill. I don't go to the dr every month I get it though and it usually corrects itself, but it comes back.