Diagnosis

Hi I'm Steph. I'm 25 and I have a nearly two year old son William who is currently being assessed for Autism. It's been clear to me since he was around 14 months old and I have no doubt that he will eventually get a diagnosis.

I'm wondering though how long it took for others to get the diagnosis for their little ones or themselves. We have Williams MDA coming up in November and I was under the impression that this would enable them to diagnose him, after a recent conversation with his health visitor I've been told that's not the case?

I'm finding it all really confusing about how he will get his diagnosis. 

Steph