I'm glad the initial appt went well.
Get the numbers of the clinics, and keep politely phoning to check how the waiting lost is going. Get your name down as being able to attend short notice cancellations (if you are, of course). Make a (nice, polite, concerned-mother) nuisance of yourself, and it may help bump you up the lists (if only to get rid of you
)
How old is your ds now? Don't listen to anyone saying there is a minimum age for dx - this is usually only to 'manage' their lists and budgets. Try to find out what diagnostic tests they use in your area, and ask when they will be administered - with dd1 I was so clueless we ended up have Community Paed appts x3 (minimum of 6 months between them, usually more like 8-9 months) before we wished up that we were being kept in a loop - none of the comm paeds we saw were qualified to dx, so all they could do was re-take history. The third one we saw was a 'good guy' and so thoroughly fed up with the crappy holding pattern (which left children like dd1 - nonverbal, severe, no play skills or functional communication at all - in limbo with no support) that he spilled the beans and told us who to ring and what to ask for.
She was dx'd less than 6 months after we saw him, from a startpoint of no assessments having been done (only history taken and re-taken). And she was only 2.8 then. It can be done when they want to (and indeed, if you went private, you would likely get your answer in a day - not always, but usually - so the 'it takes a year to dx' type statements are usually just treading water).