One of my teeth is hurting/aching. According to a diagram, it's a premolar. It feels like it's in between the teeth and possibly in the gum, and rubbing my gum below the tooth makes it hurt a bit more. It was hurting a few days ago for a bit, then stopped that same day. Yesterday it ached all day, and today it didn't start to ache until I ate something. Looking in the mirror I can see what looks like a small (tiny) brown spot in between the two teeth, and running floss between the two hasn't pulled anything out.
Do you think it's a cavity?
Is there anything that can be done, keeping in mind that I don't have dental insurance and probably can't afford it?