how long does it take to get pregnant after getting off the depo shot

So i got my last depo shot in may. i was due for one august 1st but my insurance wont cover it anymore... i started my period the day after it was due and the last time i got off the shot it took months before i got my period... then awhile before i got pregnant with mt son. my husband and i have had unprotected sex 2 times since not getting the shot... but we just assumed it takes a while to get out of my system like last time. we are not wanting anymore children right now due to getting granted custody od our niece and nephews this past monday. i am just wondering about the sitiation with the depo.