H1B activation and cap

[Ajaxfet]

I got approved for a cap-subject H1-B in May 2015. The H1-B became active on 10/1/2015. But I have not yet joined my new employer; I am still working in the USA on my cap-exempt H1-B. Will I be considered to have been counted against the cap only when I join my new employer? Or am I already considered to have been counted because my approved H1-B became

active on 10/1/2015? If the latter, if I join a little late or if I do not join or if the H1-B is revoked, will I still be considered to have been counted against the cap?