Prescribed Provera, now period won't end =/

Pryscilla
TTC and prescribed Provera. I finished 3 months abd began to get my period on my own pretty much every 28 days...but now the past 2-3 months I will have a long period for 10-14 days stop for a week -10 days then start again.....has anyone else experienced this ? Side effect of taking Provera ? What did your doctor's say?