I agree with @Punxsutawney that you would know if you’d done the ADOS OP.
My daughter wouldn’t have been diagnosed without it. She masks well and can appear to be very socially confident, school said “she is fine when she is here” (she wasn’t fine at all, but that’s another story!) I thought this is what would happen during the assessment and that the assessor wouldn’t see through the masking.
However, I listened in the other room and as I listened on to her doing the tasks and answering the questions, that was the first time I actually thought “Oh she IS autistic”! as I’d been in two minds in the weeks leading up to her assessment.
Obviously I didn’t know exactly how it was being scored, but I could hear enough to convince me. I was surprised at her responses and I actually noticed some things I hadn’t before, about her conversation skills. It was skilfully done.
The clinician’s own conclusion was that she didn’t have any doubt - it still went to panel for feedback from other professionals though, plus my detailed questionnaire, plus school information plus many other reports we already had.
To the posters who seem to think it’s an “easy” diagnosis to get, it really isn’t. I know of a few parents who have been given “wait and see and come back in a few years” even when paying a lot of money privately, it isn’t a diagnosis that is just handed out.
ADHD is an even harder one for children who mask in school, as the behaviours have to be seen in two settings