getting pregnant after depo

How long did it take for you to get pregnant after coming off depo?? i have gotten two shots, first one june 2015 last about sept and was due in December 2015 but never went for it, i got my period in march 2016 but it was very irregular i had a period then i was off then period again it happened twice as well in april and may, then became regular in june2016 and have had regular periods since then but i still havent been able to get pregnant