I've always experienced this from the very first time I had sex 35 years ago! I'm very clean.
All depends how bad! Some smell is inevitable with the various fluids and physical activity......
I had something similar happen a few years ago - it smelt like onion/garlic!? I was mortified and my boyfriend at the time said it was normal and it happens - it hasn't happened to me since then. How bad was the smell?
Yeah smelled a bit like onion or garlic or sour milk.