toddler with autism!

Hi 

we are recently going through the autism assessment with my son who has just turnt 3 years old. Our son had normal development up to the age of 16 months old and he is a complex case as he shows certain traits but is considered very high functioning for his age. His speech is very delayed and he struggles to socialise with children of his age group but he can socialise with older kids such as his cousins and he socilises well with adults. We have been going through this assessment since last year November and he is currently getting speech Therpy and play Therpy and is due to have the full blown assessment in September/October as he is due to start Nursury in September. 

how does the autism assessment work? And how long does it take? 

I do think certain policy's and rules need to be revised in regards to the assessments and how they deal with family's. People have been telling me horror story's of how long they have been waiting and that they keep it dragging but I am very on the ball with it all I mean I am the one who raised the concern and I am one who made sure he got help by brining up there policy's and guild lines. I have had one school up for doscrimation against my son as they said they can't cater to his needs without a ECHP but will take him if he has one but then in order to get one he needs to be diagnosed with autism. Honestly the fight is unbelievable but has anyone else experienced this? thank you x