A.K.
My daughter did the same thing when she was 3 1/2 - 4 months old....and guess what? Her ped said the same thing your ped said..."not teething yet"...well about a week later her first, (not one), but two teeth came in!! And since then she hasn't had her hands in her mouth nearly as often as she did then. Her hands in her mouth did cause her to spit up more but I'm not sure there is anything you can do about that. I'm very interested to see how this works out...keep me posted!