I also wanted to add that up until a few months ago I wouldn't even have considered taking him to a doctor but one of the things he does that worries me has gotten worse. He can't get a sentence out. We've been working on it but it seems like it's only getting worse. I've had him sit quietly and think about the sentence that he wants to say and he still can't do it. He says "um" and pauses forever. Sometimes it will take him 5 or 10 minutes to get out what he's trying to say.