Hello Bielz.
Welcome to the forum!
I'm not too good with describing the tanner stages but here I go:
I would say the next step is your breast mounds will start to project more or otherwise get pointy. Your glands will eventually disperse amongst the surface of your chest.
If you posted some pictures I think it would be easier to gauge what your next step of progress will be. It also is an excellent way to get feedback and advice on your NBE regime.