Did you post this info within the last month here? I can't find the post, but if it wasn't you, there's another woman out there who is experiencing this exact same situation!
I'm a little confused here. Candida, and other thrush symptoms, aren't caused by a flora that is unusual to the vaginal tract. It's an imbalance, or over growth, of a typical bacteria or yeast found in the vagina. So when your doc says they can't find anything unusual in your lab works, that's to be expected. It's an overgrowth of a usual member of the environment.
Can you ask for a detailed lab analysis, to see what it is, exactly, that's represented in larger numbers than expected?
First thing, though, while you're waiting, if you haven't already gone off white sugar and carbs, do that now. You'll likely see a dramatic benefit, as yeast thrives on sugars.
Best wishes. This sounds really frustrating.