Get it checked
If your jaw is hurting on one side it could mean you have a bad tooth referring pain to your jaw and you could have a responding swollen/sore lymph node in your neck.
Or if your clenching your jaw at night it could make your jaw hurt. Can involve cheek and neck muscles as well. Have dds check for infection on the affected side and have him check for signs of night clenching/grinding. Good luck.