How long does it take for the depo shot to work

Edit: wow you people are really unhelpful. I asked a simple question and neither of you could answer it really? Obviously I know you're supposed to wait 6 weeks and I'm not thinking of having sex anytime soon. Anyways you guys aren't doctors and even if you were you aren't MY doctor. Plenty of women get the OK to have sex far sooner than 6 weeks. And I would never try to have sex until I got the OK from my doctor. It depends on the amount of damage you had at labor.