I would call the Birth23 program
http://www.birth23.org/
they are great , they come to your home to diagnos the problem and then create a plan for solution.
at 24 months he seems a little delayed,
I really think he would benefit, my youngest was delayed and they were able to help him catch up.
besides its free.
They told me that most doctors/parents who take the wait and see approach wait too long. making it more difficult for their child to catch up.
The way I look at it, as a mom its my job to make the right decisions for my child.
If my child was sick , i wouldn't hesitate to take them to the doctor,
You have a concern for your child, why take the chance, best bet is to ask the professionals to evaluate and help you decide IF there is a delay and what action to take IF there is one.
Good luck
M.