I self-diagnosed late 40s when I was looking into the topic for my daughter (she is stereotypical inexpressive and hand flapping). I took the AQ test for kicks and was borderline. I didn't realize that expressive folks like me could be on the Spectrum. I started to consider the questions more carefully, peeling back my self-perception (e.g. I go places all the time) with reality (e.g. I go to the same two places -work and library- when scheduled). Now my score is consistently higher. DX is typically late, if at all, for women born before 1990. In my youth I was simply known as overly sensitive, overly dramatic, wicked smart, lazy and my mom yelled at me frequently "why don't you have friends?". As a young adult I was DX'd "mild mood disorder". As an adult I am facing difficulties with the recent change in workplace culture, which is aggravating my "symptoms".
My daughter will likely be DX'd at age 8. It appears my husband and son (age 5) are NT, although have traits (husband inexpressive, son hypersensitive).
I'm in Colorado also.