Hi,
I have a son that sounds very much like yours except he is 24 mths. He too is in early intervention with 4 days a week, 2x speech, 2x special ed. If you don't mind me asking, why did you chose ABA for him? Is ABA real tough for him?
Taking this post in context with your previous one, it looks like you are doing exactly the right thing. At your son’s age, it can be difficult to tell if his language is developing a little slowly or if he might have a diagnosable condition. The eye contact, the fact that he is very social, him looking like he’s attempting to say something to you are all great signs. The progress that you are reporting from his ABA therapy also is really encouraging. The best way to address your concerns, at this point, is to identify potential deficits that he may have, areas that he seems to be behind, and seek out services to help address those. If it turns out that he ends up meeting the criteria for a diagnosis for an autism-spectrum disorder, then you are ahead of the game. If he doesn’t, you’re still getting him valuable services that can help speed up his development in the areas you’re targeting. I would recommend having him seen by a specialist in another few months to see if a diagnosis is warranted given the progress you will have seen by that point.