Generally, it takes between seven and 10 hours for a dog to digest food, but the many variables mean that only your vet can tell you how long it should be taking.
But how many days after Provera will your period start? When using Provera for amenorrhea (absence of menstrual periods) or abnormal vaginal bleeding, the medication is taken for 5 to 10 days. Menstrual-like vaginal bleeding usually occurs three to seven days after treatment ends.
What to Expect From Taking Provera. Ideally, you should get a period after taking Provera as prescribed, however, not all women with PCOS do. Since Provera is a hormone, it may cause side effects, with the most common ones being headaches, breast tenderness, and mood changes.