3yr OLD WITH EMOTIONAL AND SOCIAL ISSUES

Please can you help.  I have a 3.5 yr old boy who is causing concern.  Since he was born there were flags raised to a number of issues i.e. he was a very quite BABY he was about 3/4 months old before we heard a proper holler.  When he was on the floor he sat WITH toys but didnt explore them like normal kids did.  He didnt walk till he was over 2yrs old, we put this down to the fact he was with a childminder who, as it transpired, left him in his buggy for long periods of the day.  His speech can sometimes be a bit jarbled as in he will say "theres a bus" and daddy was in the aeroplane with the dinosaur?????  although this is subsiding a lot.  He is now in Pre-school and with a new Childminder whom he loves but she is flagging his behaviour, she finds him difficult and no matter what angle she seems to come at with him it doesnt seem to work.  His Pre-school teacher pulled me aside to basically flag the same thing.  He is not grasping what the other kids are grasping, he is not interacting with the other children AT ALL.  he spends large amounts of his time whining when he cant get his way but she is unable to reason or compromise with him.  I am worried that there may be a problem and dont know where to go.  I have been in contact with the District Nurse who came on Monday and did basically a Developmental check and he has an appointment with the Area Medical Officer in March but I really need to identify it there is a problem so that I can help him and his care givers.  Please can you advise in any way.

Rgds
Sadeth