Is my child's behaviour normal

My son is going to be 3 years this month.Till 2 and half years he was at home with his grand father.For the past 5 months he is going to day care.He does not mingle with kids in the day care,only rarely he plays with other kids,when the other kid initiates.He is a lone kid at home,so recently we have been inviting families with kids to our home on week ends.At times he does not respond to the questions asked.He is good at colors and shapes .He plays building block and when he is playing,if we ask the color of the block he says sometimes ,sometimes he ignores sometimes.Also at any other time ,when we ask him something ,he does not respond at all. He has immediate and delayed echolia .He speaks out of context many times.He scribbles on paper and  with a pen and he wrote 'A and B'  recently. We have to remind him to say Hi or Bye to other people.If we remind then he says.When I leave him at daycare ,I ask him to say Good morning daily but he never says and only smiles broadly .When we visited my son's pediatrician she said he is shy that is the reason he doesn't mingle with other kids ,and suggested to take him to playgroups.For not responding she says if the child is not interested he won't respond .He is not yet riding bike.But we don't make him sit quite often .When we play ball ,he doesn't want to throw or kick ball most of the times.But he can throw the ballon up. He cries and tanturms are there.But within 10-15 minutes it goes away .If he drops someting like building blocks from the box ,he cries and asks us to pick it up for him.When we say we can help,but he should also join ,he joins.If I ask him to do something and if he is not doing, I say ' Mommy is crying' ,then I mimick crying ,after that he obeys.I suspect he has  'Semantic Pragmatic Disorder' .I am not sure how do I proceed further.We live in San Jose,California,USA .Can you give some referrals of speech therapist,Also want to knowwhat do you think about his condition .Looking forward to your reply

[tiredbuthappy]

I would contact your school district and ask about early intervention services. they can tell you how to procede.

[ginaballerina]

I think you should have your child evaluated by a special needs agency for children, one of my twin grandaughters, had similar behavior and we noticed it when she was 1 1/2 she was diagnose with what is called PDD is a form of autism, but with special need teachers and school, she is doing much better now, her social skills have improved tremdously. Look up PDD and how you can help your child.

[Natta1980]

Look into PDD