Sorry to hear that your mom thinks that this teasing you like that is all in jest. Anyway, if you say that it smells more sweaty than fishy it could just be the way that you smell or it could be some sort of hormonal inbalance. I usually suggest that it could be bacterial vaginosis because of the fish smell you mentioned but I'm not sure. You are going to have to see a gyno about this. They will listen to you intently and seriously. You will get answers, even if they tell you it's completely normal.
Best of luck.
your Mum actually teases you about this?!!! Not very nice of her, is it? Nothing against your mother, but that's kinda rude, don't you think? I would have been mortified at your age, and am a little bit shocked about this comment of yours!. Of course, I am an aging luddite (look it up). so what do I know, but.... - Ali