I have switched from implanon implant to petogen fresenius injection, however i want to switch to depro-provera. good or bad decision?

Depends: Not sure why you want to switch to Depo-Provera. Some insurances limit which medication they will pay for. The injectable birth control meds do have frequent side effects of spotting for up to 3 months. If you need contraception it is a method in which you can get the shot and forget about it for 3 months. Consider condoms and practice safer sex as well to protect against HIV and other diseases.