What developmental delay does my 4 year old have?

Your sons symptoms sound very similar to my son, and my son was just diagnosed with autism. Most doctors are the last place to go for help. My sons doctor sent me on a wild goose hunt to see what specialist will accept his insurance(most don't for autism). After 8 months of no help from his doctor, I found out about a place called Regional Center. I don't know what state you are in but if you are in California, try going there. I also recently found out about DAN(Defeat Autism Now) doctors. I know how hard it can be trying to get answers from a regular pediatrician, so you should really look into a DAN doctor who has more experience with children with autism.