If you have you the depo shot once how long does it take for you to get your period again and how long does if take for you to get pregnant again?

the first time i got the shot i was okay on not having my period for the first two months then i spotted until my next shot. I'm due for my 3rd shot, and this time it was only a week-2weeks (i lost track). but its just spotting, not like my usual period.