Dull Jaw Pain

There is a dull pain in my left jaw that occurs when i chew food.
Earlier today, I ate lunch no problem. Dinner, however, involved me cringing at every bite. It seems to be almost a cramp or severe tightening of the muscle. It does not hurt when i open or close my mouth, only when i chew.  

My wisdom teeth have yet to be removed, and im fairly confident they are starting to come in.  I also am an avid gamer and tend to clinch my jaw in tight situations.

[Jerome Tsang, DDS]

I would recommend getting it checked out.  They can hurt while they erupt so its possible you may be hitting a certain spot from time to time but its odd how it can hurt for a whole meal and not hurt the next.