Do you mean that we can take provera until week 12 without any big risks? I am a bit confused as I just found some information from MedlinePlus Drug Information: Medroxyprogesterone

"Medroxyprogesterone should never be used to test for pregnancy or to prevent miscarriage during the first few months of pregnancy. Medroxyprogesterone has not been shown to prevent miscarriage and may harm the fetus."