CURIOUS

Hi, new here :) 

I recently took my 11 year old son to the GP because after years of dealing with a really draining Child I thought it was time to get some help. By draining I mean, hard work. So so naughty, demanding, needs to be in charge, meltdowns that last hours. The list goes on. I went thinking maybe he had ODD part of ADHD. I told my doctor everything, he spoke to my son and then he got up and started looking for something. Finally he printed out something and handed to me. Told me he's not ADHD but he does have some concerns. Told me to answer the questions and bring it back on my own to see him. He wanted to talk to me alone. After looking at the questions, they're for Autism? So naturally I've done some research and he does tick a lot of the boxes, for some that I just thought was his personality and didn't think much of it. 

My question is, my doctor said to me while you and I have been talking I've been observing (looks down at my son). Does my Doctor think my son is Autistic and can he pick that up in 20 minutes? 

Thank you.