32 month old behaviour

my 32 month old son has speech delay. He is not talking his sentences yet. He understands everything I say.
If he wants water or milk he will say "wattu" for water or "bottu" for milk. He used to watch a lot of TV. Now, I am turning the TV off.  I was concerned about his speech at 24 month old but our doctor said to give him some time. We are getting him evaluated next week. He is repeating the words and sentences from TV all the day. When we ask his name he is not telling. He will say no to most of the questions we ask. But, he knows them very well. All the day, I will be asking his name and he will say 1 or 2 times. He points the pictures in books and he will name them when I ask him. He knows numbers from 1-20 and all the alphabets. When I ask him about the picures in book, he will name them immediately,He enjoys watching kids playing. He doesn't go to strangers. I joined him in daycare this week only. My sister's son is autistic. So, we are reaally concerned about his behaviour. He is also lining up the blocks.If I say no, he will stop and he won't repeat that. Can anybody please help. My friends are telling me that I am worried about him keeping my sister's son in my mind. I used to agree with them before but not now. He is always repeating the words from tv. He know the rhymes well and sings them while he is playing. But, when I ask him sitting beside him," can u sing that rhyme ",he will not sing. The problem is he is not answering to our questions like " what is your name" .He knows all body parts.When we ask him he tells us only 1 0r 2 times but not everytime we ask. When he wants something, then if we ask his name, he will answer. Thank you for reading this. It's a really long one. can somebody help?

[specialmom]

Hi,  I think you are a good mom for being concerned about the welfare of your son.  And I think it is awesome that you've taken the step to set up a speech evaluation.  He sounds delayed in the expressive part of speech as well as articulation.  I'm glad that his receptive part is function better and he understands you.  Lots of kids have speech delays and they can do amazing things with early intervention.  It can change the course of a child's life.  

As far as autism, he really doesn't sound autistic to me.  He isn't shying away from communicating with you----- right?  He makes eye contact and tries to interact, right?  He will play with you or others. Does he do imaginative play?  He is learning lots of things it sounds like.  I think as you work on his speech with professionals in the field, if he is mildly autistic, this will come out then.  

Once your child turns three, you can also have your local school system evaluate him and they must provide early intervention for him by law.  It is usually a preschool program with services provided at school.  (its free!)  

Try not to worry in the mean time.  You've done all you can do at this point.  My son has a delay of his nervous system called sensory integration disorder.  It was hard in the begining figuring it all out and not be terribly sad by it all.  But as he is now 5 and doing awesome after early intervention-----  I can only say try not to worry as they can do amazing things with little guys.  And your son sounds very bright which will make his catching up easier.  Good luck.