How long should my period be lasting? I have not have a period since December 2013, I took the Provera 10mg for 5 days, May 1-5, period started on May 14 (spotting very light), it really started bad on May 15, it is now May 20, and it is still hanging around. My periods before they stopped happening were always 5 days in length, but it doesn't seem like this has any intention of slowing down.