Vinegar smell down there

Okay, super weird. Supposed to get my period in 3-4 days (but hopefully not) and when I went to the bathroom my vagina has a weird vinegar smell. I have no itching or weird discharge but it smells strange. I also am undergoing fertility treatments so I have had all of the tests everything is fine and I had <a href="https://glowing.com/glow-fertility-program">IUI</a> almost two weeks ago. Anyone have this? It’s so yucky!