My step son (2 he will be 3 in August )shows some different behavior. I.e. He will just stare and…

My step son (2 he will be 3 in August )shows some different behavior. I.e. He will just stare and blink at you. Sometimes if you talk to him he will just stare and blink at you. He is also behind like he his speech is fairly behind. He is learning to say more words now.His bio mom has put him in speech therapy. He's also been tested to see if he has autism. Is this normal ?