I was o the depo and the last shot i had was in december 2008 so it ran out March 2009 iv fallen pregnant once since then which was March this year but misscarried. My gp told me it could take upto 18 month for it to be completely out of my system x
On the shot you either bleed non-stop or your period stops completely. It has a more likely effect of just stopping your cycle all together. And yes, it can take 6 months to a year for the shot to fully leave your body. You can try at any time, but until you ovulate you won't get pregnant.