It is teething? Rolling over?

My baby is 4 months old and up until just recently he was sleeping pretty much through the night and generally a very happy baby. Just this past week or so though he has been starting to be very, very fussy and constantly sucking on his hands and fingers even when he has already eaten. Last night he woke up about four times crying I gave him some tylenol because he was warm and some herbal teething tablets. He is also drooling like a faucet. I have a four month check up next Wedsnday but just wanted to know if anyone else has had this happen? Another question I wanted to ask anyone is my son keeps trying to roll onto his side from his back and he is pretty much there but he cant stay on his side he wobbles and ends up on his back again and very angry. Is there a way to keep him on his side? I have a sleep positioner but he HATES it now. Any suggestions?