I probably wouldn't be worried either. DS speaks really well for his age - and everyone who meets him comments on that fact - so I would assume that most kids don't really start talking - like really talking, not just jibberish (I say DS speaks Chinese most of the time ) until maybe 2 and a half? I know from all the other kids I've met, I still can't understand what they are saying at 4!!! LOL

If it didn't worry you before - and it took one persons comments to worry you - then I would think that you know your son better than that person.

However, having said all that - it never hurts to get peace of mind - IYKWIM?