Communication

Talking?
I was a communication major and I understand that clear communication is important in order to be understood.  We started the baby signing dvd when Kai was 6 months because my friend Judy did it with her genius girls.  I read that it helps cut down on the child's frustration to be understood.  I know that I communicate better when things are written down and I can see the written word.  Depending on the situation or who it is, I'm usually not the best verbal, oral communicator.
Kai is 17 1/2 months, but not talking yet.  Sometimes I wonder if it is because he is a boy, he is growing up with 2 languages, or perhaps genetics (his dad didn't start talking until after he was 2).  I know that he understands what I'm saying most of the time because he can point to things like ball, cat, dog, baby, car (when he feels like it and he still doesn't point to who his mom or dad or tutu are), when I start reciting a book he can go and grab the right book, he can do baby signing (like dog, milk, more, eat, cereal, apple, all done, please, bye bye.)  He can make the sounds mama and dada and uh oh,  babble the consonants b,z,g,d, m, but he doesn't use it in context.  We go to plenty of play dates, mommy groups, gymboree, the park, the library, read books, watch baby signing dvd.  I see other kids the same age who are growing more and more verbal than Kai.  Some of them are also boys and growing up with two languages. They can say lots of different words and repeat.  They seem more social and interactive.  I'm not sure if I should be concerned.  Sometimes I wonder if he has a hearing problem because he doesn't respond most of the time when I say his name.  I've been reading about autism and speech delays, but I'm not sure.  I can think that Kai is just shy or that's just how he is.  He can also show an affectionate, funny side to him.  He takes his time to warm up to new people and is very cautious and observant before jumping into anything.  From what I've been reading, he should be talking a lot more than he is.  I'm thinking to talk to the doctor at his 18 month appointment for a speech pathologist. 
I don't really think he has autism, but I am concerned about his lack of speech.  Kai doesn't seem so frustrated which is good and he seems pretty content staying quiet.  I guess he's able to say what's important to him and get his simple message across.  He can ask for his food and drink.  He can point to what he wants.  He can bring over which book or toy he wants to play with.  He can laugh when he's happy or cling to me when he's scared. 
Anyways, I pray that God will give Kai the ability to communicate more and more.  I pray that I can love Kai for who he is and not expect anything more and also not to worry if I don't need to.