With oral thrush, you should also be able to see curd like patches in various places, like down between your cheek and gums. Sometimes it's visible as a thin whitish/slightly opaque film on the inside of your cheek, or on the underside of your tongue. But you don't always see every sign.
Another sign that people don't mention much is that it can establish colonies along side the roots of your teeth, or dental work, esp. root canals/posts. It will fill in the gaps between your teeth pretty quickly after a high carb meal. It looks and feels as if you just ate a piece of Wonder Bread, though it might be an hour after a meal. Kind of nasty.