Birth control

Cassie • Am 25years old n married
I've been on birth control pill at the age of 16years old n than put on the depro shot at 18year's old I've been on that for 6years n now I've been off the depro shot now for May 23rd of 2014 n now am having a period n I was wondering how long would it takes to get the depro completely out of my system so I can get pregnant