20 days late

I have PCOS and I'm 20 days late. Two weeks ago my doctor did a progesterone test and it was low, no sign of ovulation. She put me on provera to jump start my period but it's been 8 days since my last pill and still no period. Usually on provera I start 2 or 3 days after the last pill. I keep having symptoms of something happening but no period... Nausea and light cramps as well as other symptoms. Could I be pregnant? Or does it just mean provera didn't work? Has anyone experienced this?