P.G.
lots of kids flap. But re. the language delay, I would contact early intervention about that. Language delay is a common symptom of autism, but it's also it's own thing as well. Best to address that so you can give him the support you need.
If he is diagnosed on the spectrum, PM me, or visit my website - autistikids.com My little guy was diagnosed at 4, had some speech therapy for a few years, and is going into 3rd grade next year (age 8). Mine is SUPER social, but awkwardly social ;)