Face is sore and slightly swollen on the right side from the bottom of my cheek bone to my jaw line. its very tender and feels bruised. what could be?

Could be many things: It could be many things. A detailed history taken by a medical professional will help to narrow the possibilities.

Face swelling danger: With this pattern, if you have not had an injury, you could have an infection coming either from a tooth or sinus now involving the overlying skin. This is not a safe situation, and you should be seen today if possible. Infections can spread rapidly and you probably need to be on antibiotics. Good luck!