K.L.
Its definitely related to the shot. I had been on depo years ago without any problems. After I had my son, I went on depo again. Between my 1st and 2nd shot I had a 2 wk L. period which stopped a few days after getting the shot. 2nd and being due for my 3rd shot I had a 4 wk L. period. I switched to the pill at that point and I bled for another 5 wks until switching to another pill. The dr said it was all related to depo.
I've now been on Ortho Cyclen for over a year and am completely 100% satisfied with it!