My little boy has been dribbling excessively for the past few days and biting down and chewing on his fist. He is also slightly off his bottle and not finishing them like he normally does. Could he be teething? He will be 11 weeks on monday and seems a bit early but other than that I don't know what it could be. He is soaking his clothes in saliva. He is also a little more grumpy than normal?