Is provera a BCP? If it is, just skip the time you are supposed to use the sugar pills (the time you would get AF) and start the regular pill for next month... you won't get AF.
That's all I know to do that works for sure.
If you are worried about horrible PMS symptoms, cramps, etc, try using natural progesterone cream (that helped me a LOT), or try this product:
http://www.mynsp.com/naherbs/product...?stockNum=1812
It is a natural product that is mostly vitamins (won't interfere with other vitamins you take, you only take it for the 10 days before your period is due), and it helps reduce or eliminate PMS symptoms, from cramps to headaches to irritability... it is a WONDERFUL product. When my brother was first married, he and his wife lived with my parents (and me) and we used to THROW monthly maintenance at her! ha ha ha Use it as directed, even though it seems like a lot to take... honesly, nothing works better!!