When I came off of Depo Provera
, my cycles were all over the map for 2 or 3 months at least. And
if you have been using protection, it is unlikely she is pregnant, providing you are using it properly.
If she is a week late,there is a small possibility she is pregnant. Regardless, taking a home pregnancy test right now will at least serve to put your mind at ease, the wondering and worrying are always the worst. If in fact she is pregnant, please don't worry too much.