Sex problems

Hey ladies so I’m not too sure what’s going on, I’m 1 day to ovulation, me and my fiancé have been having more regular sex and are currently NTNP (not trying not preventing). But every time we have sex my vagina burns for at least 20 minutes after the sex. I’ve been having UTI’s and yeast infections fairly often (last one was about a month ago) (but lately I haven’t had any) but I’m still having the burning. What do you think this could be?