DS is 3 next month. For the last few days he's been complaining about his tooth hurting, usually when he's eaten something. He's really dribbly, to the point of soaking through his top like when he was much younger. I can't see anything wrong in his mouth and he had a dentist checkup a couple of weeks ago. Could he be teething? The dentist confirmed he has all of his teeth, but could they be pushing up or shifting and causing him pain? He's a bit grouchy sometimes but otherwise ok.