usually it's bv and not yeast. darn shame the provider you saw didn't do the proper testing they should've :(
at this point, go and be seen again by a gyn and make sure they take the time to do a proper exam and testing. a lack of discharge doesn't mean a lack of vaginal infection.
sometimes a lack of estrogen is the issue too and topical estrogen creams are needed.
grace
Follow up with your Dr, can't diagnosis what an itch could be