The shot ?

Should I get the shot if I'm not sexually active ? I have went through two types of birth control since February , Ortho Tri-Cyclen Lo & Ortho Cyclen & they haven't helped my periods at all . The first one made them light & short but I had horrible cramps , worse than they ever were before . The higher dosage one made them heavier than they used to be & even longer but I had no cramps just headaches . Is there another option like the shot ? How would I tell my doctor that I want the shot instead of the pill . I know all of the side effects of the shot & I'm comfortable with them . I'm just really tired of taking a pill that is supposed to help my periods but making them worse . Can someone help me ?