Can anyone shed some light? Worried about my 20 month old's

My son is 20 months old and he is not speaking yet. He says Ma ma ma and Da da da but I'm pretty sure he doesn't know what they mean. His Dr. said he has an expressive speech delay but that he is not concerned about his development otherwise. But I am and I'm wandering if anyone can shed some light? Maybe someone that had a kid with the same behaviors that turned out to either be fine or to not be "fine".
Things my son doesn't do that I feel like he should
-Speak
-Point to things, if he wants something he will go by it and cry but won't point to it
- Listen to me or his father- he understands certain things but not most and he flat out ignores us a lot of the time when we talk to him.
- Does not always respond to his name
Things he does do...
- Smiles, laughs, looks people in the eyes
- Plays with his toys and his older brother
-Babbles a lot

Also, sometimes he will just zone out and I don't know if it's because is pacifiying himself by sucking on his bottle (because that is when it happens) but he will go in his room, shut the door and I'll catch him in there laying on the floor just staring around sucking on his bottle. He also gets very aggitated when something is wrong because he can't speak so he screams and fake cries.

I am not asking anyone to diagnose him. I have a follow up appt with his pedi in a couple weeks. He told me to read to him 3 times a day and we'll see if that has any affect. So far, it hasn't. He likes when I read to him but it's not prompting his speech. So basically, I'm just curious if anyone else has had a similar experience, a child with the same behaviors who either did end up having a "problem" or didn't. Thanks in advance!

Id at least be gettin him tested for speech therapy. It can't hurt. It doesn't diagnose him with anything. It just helps him not get too far behind and it helps him get early intervention so he will hopefully catch back up quicker.

http://www.php.com/services/early-intervention-infants-toddlers-0-3

They'll set you up with a SLP and do home visits. The SLP will teach YOU how to teach your son and different little actives to do with him.

I Followed my SLP's plan to a T and my son went from not talking at all to not shutting his little gabber mouth!

Oh search and see If you have "early headstart" or "early on" there. They may be able to offer some help.

Quoting kitermom:" http://www.php.com/services/early-intervention-infants-toddlers-0-3 They'll set you up with a SLP and ... [snip!] ... do with him. I Followed my SLP's plan to a T and my son went from not talking at all to not shutting his little gabber mouth!"

Ahhh, that's so reassuring to hear!  

Quoting lolajessup:" Oh search and see If you have "early headstart" or "early on" there. They may be able to offer some help."

I will look into that, thank you!

Quoting Giovanni & Armani's Mama:" Ahhh, that's so reassuring to hear!  "

Good!  

So in Oregon they do an ages and stages interview and from there they will do a secondary one. Since he is under 3 they will test him for everything. DO NOT talk up his abilities. If he's not doing something for the testers then just let him not do it. The more he "fails" the more free education you can get. If he gets more help than you want you can always decline the help with no worries. If that makes any sense.

Quoting kitermom:" Good!   So in Oregon they do an ages and stages interview and from there they will do a secondary ... [snip!] ... you can get. If he gets more help than you want you can always decline the help with no worries. If that makes any sense. "

Totally makes sense and good to know! I am pretty sure his pedi wanted him back so soon so that if there's still no progress being made we can get on this early and he can refer me somewhere. Good advice too because as you know, as a Mother you want to talk your kid's abilities UP  
Thank you! 

I would check with early intervention in your area and get started on a speech and language evaluation or get your pediatrician to recommend one through insurance. You should also check out www.littltalkers.com a free speech and language website. You can check out milestones and watch free videos with tips on how to help promote speech and language skills.

Quoting speechie:" I would check with early intervention in your area and get started on a speech and language evaluation ... [snip!] ... website. You can check out milestones and watch free videos with tips on how to help promote speech and language skills."

Awesome! Thank you  

Do you do baby sign with your baby? Maybe that would help with the frustration he has when he can not express his needs? Also, it was suggested to me with my son to try and not aknowledge his request until he made some sort of verbal cue to get my attention and then name the item that is requested while having direct eye contact. Also visit your local elementary school. They shoud be able to direct you to a resource for infant and toddler programs to assess for any special needs he may have. Good Luck!