The difference may be that the depo shot does not contain estrogen.. Unlike all other birth control pills and the patch. It does contain progesterone which is a hormone.. Estrogen is often the culprit that messes with your blood and it's flow. For instance that's why they say not to take bcps or to take the lowest estrogen doses if you have bad circulation, migraines.. And that's why it can cause blod clots. I would see about a third opinion.. And ask specifically about the depo.. The doctor may be lumping all birth control together to be safe.