What Causes Delayed Periods Despite Taking Provera?

I took my last depo shot in feb 2014. I still have not had a cycle. I was given a prescription for provera to take for ten days, and was told I would have a cycle within 14 days. I finished the last pill on 3/13. Still no cycle. I ve had bloodwork done that has all come back normal. Now my dr wants to put me on another round of provera. what could be causing the absence of my cycle? early menopause? Am i DYING???