I really can not impress that enough.
No doubt if you have searched the Internet vigorously enough to have found this post, you have read about the importance of Early Intervention. And, if you have read enough about Autism, I am sure that you have read that early detection and early intervention can dramatically improve the prognosis of those affected. I am here to reiterate and amplify that the first step for parents of young children with developmental concerns is to CALL EARLY INTERVENTION, NOW.
Later, I intend to go into great detail about the "developmental concerns" we had which caused us to call. We called when our little man was just under 2 and a half and only after we were clubbed over the head with it. But for now, if you find your self saying things like..."he just needs more time..." or "maybe its just a second child thing" ... or "my cousin had a son who didn't do that until after he was 3..." my vote is that you call EARLY INTERVENTION, NOW.
Why? It is an all reward, no risk endeavor. You get a team of qualified individuals to come to your house, play with your child in a manner that enables them to evaluate your child's development, and then tell you what they think. Best case scenario, you are an overly diligent parent of a child with no developmental delays. Worst case scenario, you are an overly diligent parent who caught developmental delays at the earliest point.
It is literally a no brainer. If you have any developmental concerns, you should CALL EARLY INTERVENTION, NOW!
Spread the word.