J.N.
1) If he's not affectionate (hugging, kissing, showing emotions) then it would be a good idea to check for autism. That's the big sign the therapists said that they look for when they are evaluating a little one.
2) The best thing you can do is get him evaluated. I did that with my son (he turned 2 in March) and the program he's in is a miracle for our family.
I didn't feel like there was anything wrong, but my husband did. A few of my friends had their kids tested w/differing results. That made me more comfortable with the idea/process. I really wanted to believe that eventually he would talk.....What finally made me get him tested was that we did a library program for 2 year olds and he just seemed way behind where his peers were in terms of speech. 2-year olds can vary a lot, but you notice when his peers (boys and girls) are talking and he can barely say mom or dad or "no". I wish I had gotten him tested sooner because it would have saved us a lot of tantrums and confusion!
Look at it this way, if you get him tested and there's nothing wrong, then you've saved yourself a lot of worry. If you get him tested and there is something wrong, then you've caught a problem early and you can get him help.
You are not alone. There are a lot of other kids/parents in this situation. In fact, a mom I know is a speech therapist and her son is in speech therapy because he's having problems w/speech (ironic, huh?). It really can happen in anyone's family.
Here, in Michigan, we have programs through the public schools and, if he/she qualifies for services, then it is free for the family. It's really worth your time to get him checked out. There are also private clinics and hospitals that have speech pathologists. I don't know what your state offers, but it's worth looking into. Good luck to you!
Let us know what you decide and how it works out for you.