I don't think your son has autism, since he sounds normal except for the speech.

Let me share you my story. My son can not talk when he was 2. It was his behavior, not his talking ability, that made me worried at that time. He was very tantrum, cyring all the time without any obvious reason. So I took him to see his Doctor and she referred us to a medical center where he was ????uated by a group of doctors. At that time, they can not conclude whether he has autism. Since he was development delayed, he was enrolled in the EI (Earlier Intervention, every state has this program) where he received speech, OT, development thearpies. That was great help for him. After 6 month, he was r????uated and the doctors said he doesn't have autism (at that time, he just can say about 20 single words at the age of 2 and half). He is 3 now and can say a lot of words. Comparing to a normal 3 years-old, he is still delayed, but I am not worry much. I am sure he will eventually catch up.

I belive the EI program was great. Without it, my son couldn't make such improvement in one year. Since your son can not talk at 2 and half, I am sure he will be qulified for EI's speech therapy.