Cavity?

Have any of y’all ever had a cavity? I’ve never had one before but I think I might have one now. Honestly not really sure. Could brown spots mean cavity or could it be plaque , stain, etc? I don’t really know what cavities look like 😂 I have some pain but it’s not on that tooth. And I know the pain is most likely from my wisdom teeth growing (that’s where the pain is) and I’m getting those out in a few weeks