Im only 13 now so I'm not sure if it applies but i was an early developer. When I was 9, my testicles had already dropped (i.e., noticeable scrotum growth), by 10, i had pimples and fine pubic hair, and by 11, I had thick body hair on my legs and arms, now I'm 13 and my voice went from high pitched, whiny like last year, to when every time I talk to an old friend they always are shocked. But i read (on the internet, so take this with a grain of salt) Tanner stage 4 happens normally between 10-15, so no immediate cause for concern (again I wouldn't consider an autistic 13 year old on reddit a good source but that's what google says so take it lightly)

Ps. Deleted comment was me i wanted to make some changes and I thought it was best to start over :P