With DS1 (now 10 with AS) it was first suggested when he was about 4 by my friend, she read "A curious incident of the dog in the nighttime" and said that DS1 spoke exactly the same as the boy in the story.
I put it out of my head, as apart from DS having very intense obsessions - 18months he knew the digestive system inside out (all enzymes etc), wouldn't eat anything without knowing what use it was to his body, then from 2 onwards tudor and roman history, DS and I were perfectly happy. But my sister, who is a SALT, said all men have autistic traits and DS1 is fine.
Then DS started school. How things changed! Suddenly he had to fit in with other people - e.g. it hadn't mattered before that it took us a couple of hours to walk a 10min walk to the shop as he investigated every stone and stick. Now he had to abide by school rules. He spent the first year or so at school hidden under a table, if they pulled him out he tantrummed baddly. He tantrummed going into school. He tantrummed coming out of school - could take an hour to get from school gate across the yard to the car... Transitions were definitely not his thing!
So when HV came to see DS2 (born in October after DS1 started school) I told her in tears all about DS1. She said, "sounds like AS, I'll refer to community paed". Suddenly I realised all the symptoms of AS that DS1 actually had - he would talk to people with his back facing them, no eye contact, massively stuck to routines, couldn't cope with new things, e.g. if we said "let's go to McDonalds for lunch" he had to know which MDs, which table, which food etc before we could get him near the car. Couldn't cope with choices. Sensitive hearing. Would only wear certain colours and textures.
Comm paed referred to CAMHS, after 3rd session with social practioner there she decided we needed to see Psychiatrist for AS dx, but comm paed decided to overrule her and say was School anxiety leading to AS traits.
Removed DS from school and home-edded him. Moved areas, put him back in school - where he was happy. Still very anxious. Referred by GP to anxiety team. They said 1st appointment - this is AS, referred us to ASD team. 4month waiting list. Had dx within couple of months of seeing them.
DS2 has classic ASD symptoms - no language til nearly 3, no pointing, no eye contact, tantrums at the slightest change etc etc. When DS1 was seen by ASD team they said they would put DS2 on the school referal list as a high priority case(they were sure he had ASD) as the pre-school list was so long, so he wouldn't be seen by them before he started school in 6 months time. The school team waiting list was meant to be 4months long. Well DS2 has now finished reception and still not got to top of the list 18months later. So I treat him as if he has HFA and we get along ok. So our waiting list has suddenly massively increased, they are doing 'staff restructuring' ie laying off staff involved in the dx procedure :(. Last time I checked they still didn't know when he would be seen. However, as I know that having a dx won't make much difference at the moment, I'm happy to wait. DS2 unlike DS1 is getting on exceptionally well at school, he may not have friends but he is loving the work. The only difference a dx will make is he could get a prescription for melatonin and I could desparately do with some sleep!