Why is my body so confused?

I know my body is confused and out of whack. But even when you give it medicines and EXPECT one behavior, it will do something else completely. I have been taking my 4th round of Provera. Once the medicine is complete (a 10 day dose), a menstrual cycle should start within 3-5 days. In the past its usually been the day after or maybe 2 days after the medicine. However this time, it started BEFORE I even finished the meds. I take my last pill of Provera today (at lunch) and somehow my body decided I should start my "fake" period this morning already. I just don't get it. I will have to call the doctor tomorrow because I don't think that is good that it started before the meds were over. SO today gets to be "fake" day 1 for the 4th time. I will start the new Chinese herbs I got on Thursday and add to the pill count. If I don't have a cycle on my own by the time we get to the next day 35 by the new count, we can do it all over again. Get ready to start counting........