P.S.
I wouldn't worry, my son had the same problem. He is now three and was just evaluated for preschool. He still doesn't talk much, (2 word sentences) but passed for everything else which means no extra schooling right now. Knowing when he was one that he wasn't making much noise, we taught him sign language using "signing time" videos. He loved it and we never had the "terrible twos" he was able to communicate with us. His dr is very happy with him he agrees that my son will talk in his own time. Lately he is trying new words but there is still plenty of time.