I Believe My Toddler Has Aspergers, But I'm Not Sure
Here is the thing: a diagnosis is only as good as what you get from it: therefore, how good the person is who's doing the diagnosing is critical.
Our school "diagnosed" my son with AS at age 7 or 8. Then they essentially walked away. I'm only blaming them a little - schools are generalists, not specialists, and when you think about the host of stuff that can be causing behaviors in kids, it's difficult to expect them to get it right without some help. However, they offered us no explanation for the mood swings, no explanation as to why he was fine for months at a time, no explanation as to why he had pretty good social skills (he was one who was fine up until age 9 or so; he didn't make that particular jump.) and no help other than a series of "accommodations," like using a calculator or being able to leave the room - but no interventions, nor even a suggestion of which interventions we should look into.
Then, in 4th grade, all heck broke loose. We went to a specialist in autism: a comprehensive unit run by a pediatric neurologist. We were given the ADOS (the gold standard autism diagnostic test.) More importantly, after the ADOS, the psychologist sat down with us and EXPLAINED it all. She outlined DS's specific deficits, and made us get a pragmatic speech assessment - that turned out to be the big one that was driving most of the anxiety and really negative scary behavior. 9 months of speech therapy later, most of the really serious scary behaviors - gone.
My son's still autistic and still suffers from deficits. He will always (thankfully) be "different." But he can learn like gangbusters, and once he figured out that he could learn the stuff that he thought was a mystery, there was no stopping him. He's still rigid, but is slowly, slowly learning to unclench. He still struggles with "theory of mind" issues, but he's at least learning to look out for those kinds of problems: he now knows to backtrack and ask questions if people get confused.
I think the idea that autism is "trendy" is BS - but I do think there are an awful lot of people out there that think their job is done once they've stuck a label on a child. The label is important ONLY if it offers you DIRECTION. All this to say: find a specialist, and see what they can tell you - I'd also recommend that you check with your insurance first and start with whatever they cover.