Teething? HELP!

So I think that Eli is teething, because I can't pin his symptoms on anything else. But I can't feel or see a tooth in his mouth anywhere, which is the perplexing thing. Anwyay, he has, in the past week, begun to drool excessively, bite on anything he can get into his mouth, refuse to eat more than an ounce or two at a time, chew on the nipple of the bottle instead of sucking on it, wake up several times in the middle of the night (very unlike him), and fuss like crazy during the day (very, VERY unlike him). He doesn't have a fever, and he otherwise seems fine.

To all you moms out there... Do you think Eli is teething? Are these the symtoms? Why can't I feel or see any teeth in his mouth? Any advice you can give would be much appreciated! I feel bad for him because he seems like he's hurting, and I'm getting a little worn out by all this fussing and waking up at night. Good thing he's so darn cute! :)