It is apparent by his call of your bet on the flop that he has a hand...a queen is possible but he may be worried of his kicker. A pocket pair is also a possibility. He probably thinks with your check on the turn that you're weak and that he can push you off the hand on the river. I think you're most likely the best at this point and the pot-odds are pretty enticing...I call here. If you're wrong, you'll know for next time. It's only $22 after all.