fishy smell & sweating down there

So I’m back to college and I have to walk everywhere and it is SO hot & ive been sweating EVERYWHERE. I noticed my body odor in general being unusually bad. I usually don’t sweat that much and don’t have bad or even noticeable body odor, but I’ve been noticing especially that my vagina smells like fish. No itching or burning or anything. I haven’t been doing anything different w taking care of her other than stress, sweating, and possibly a bad diet (not eating as much as I should) do you think it’s bc of mainly sweat and a bad diet or possibly BV, she’s never smelt like fish ever until now. I’m also expecting my period soon so could that be a contributor? Also advice on how to get rid of it?