Birth control question

Courtney • Baby Caroline was born 7/29/18😻 #Policewife #FTM

I’m taking a progesterone birth control since I’m breast feeding... I know it’s critical to take it at the same time everyday and i have been, but is it like how birth control used to be as in it takes at least a month to start working and preventing pregnancy. I really don’t wanna get pregnant again yet but I hate condoms too! Lol, so basically how long does it take for the birth control to kick in