When does The Shot (Depo-provera) become effective?

Jasmine

My boyfriend and I have been together for over two years and have been sleeping together the majority of that time. I just took the shot

about two weeks ago. A few of my friends have gotten it and every one of them was told a different time that it became effective. I'm mostly just making this poll to see what every one on here was told. Comments are appreciated also.

Vote below to see results!