Maybe I’m over worrying?

My son will be 20 months this month. He is a very bright little boy. He studies something to get it down. Although, I’m worried about his hearing. He’s not really talking yet. He says mom, da, and no but he babbles all day. His doctor said it’s normal that at 18 months he should be saying at least two and at 2 years, he should be saying at least 6. My other concern is that he will be standing not even five feet away from me and I’ll say his name and it’s like he can’t even hear me. I will repeatedly say it and he will not look my way. I have to pretty much touch him for him to notice. Which five months ago, it wasn’t like that. He would actually answer to his name. My husband is currently a stay at home dad and has no concern in this so when I ask him to bring it up to the doctor, he doesn’t. My son was saying “hi, hello, thank you, mom, da and dog” five months ago and now it’s all just babbles. He picks up hand controls and making sounds so quick but he has no interest in learning words.

I am pregnant with my second child and working a lot more than I was five months ago. So I guess I could just be obsessing over making sure my first baby is not going without. But it all deeply worries me. He is a big mommas boy, very happy little boy and I just want to make sure he’s not going without it that I’m failing him in some fail.