My 3 month old baby doesnt babble. Sleeps alot only cries and wakes for milk. When we talk to him he doesn't make any sound like other children. Most of time he is not interested to talk. Also smiles less than other children. When awake that time also if we talk doesn't make any sound only shakes hands and legs. Pls guide. Other children utter sound such as angeeeeee aaaa ooooo. But he doesn't.