2 year old who is behind with his speech

Hi. Was wondering if anyone else has a toddler that won't talk. My little boy is 2 years and 4 months old. He only says a few words. It is getting very frustrating for all of us as especially him. I have actually got an appointment with his GP this afternoon to check his hearing is ok, just want a to find a reason why he is so far behind with his speech. He also shouts a lot and is very loud especially when he cries ( but then his dad has a loud voice as well so don't know if he just takes after him).

Don't know what to do if the doctor says he is fine as have no idea what else I can do to encourage him to talk as have tried everything. We have even put him in a nusery a couple of afternoons a week in the hope that being around another children will help.

Anyone else in this situation?