pregnant after depo shot ?

Diamond

i got pregnant & had an abortion. the same day i got the shot january 3rd 2017 , went through with the 4 months & never went back to get it again. it’s been a year and 6 months and it seems to me that i’m still on BC and can’t get pregnant ! i read online that it could take up to 3 years to get out of your system. thoughts or anyone experience this ?