Trying to stay fresh

Ok me n my fiancée r having sex I'm 20 years old n I wonder all the time when he goes down on me does my vagina smell fresh. I drink water but not like I should n I take baths. I still smell a odor when we have sex he said he doesn't smell anything but after sex I smell a odor. It's nothing bad like it does smell horrible but kinda like piss r fish. I was wondering what I could do to fix that. Any ideas? Please help.