Thank you both for your responses. I am hoping that is it only dental stuff. But I have looked at his teeth, as best as I can, and gently pushed on them to see if they are sensitive, but it doesn't seem to bother him. But it could be a back tooth that I REALLY can't get to.
A couple of years ago when he had to have his fang pulled, it was obvious what it was and the tooth was loose and he'd flinch when I touched it.
UUGGHH!!! I still have to wait another week!!! I could take him in early...but he is due for some shots, so I figured I'd get it all done at once.

Thanks again for your thoughts.