Although kinda helpful, the Tanner stages are incredibly oversimplified and not always... exactly accurate.
So even though you are technically 'Tanner stage 3', you might have gone through a normal puberty.
There is a chance you might have androgen insensitivity syndrome and/or be intersected... but I just kinda prefer
to ignore the Tanner stages completely, to me they're sort of useless

Hope that helps XD