provera

I started provera last month. I got my period march 1st. On march 24th I started cramping and back ache and went I wiped in the restroom it looked as if I started my period. Later on when I checked, it was just brown spotting. I have been spotting for two days now. I am so confused as if it's my period or just spotting. I am suppose to start provera again 16 days from the first day of my period. Help!!