Help! Month long period maybe due to depo??

Let's talk about pms! I have been on my period for over a month now and not light. Heavy with serious back pain. Trying to get pregnant is very difficult when AF is with me all month long! Had this happened to anyone else? I had the drop shot back in September and never had it again. Doctors said that it's my body trying to get back to normal but the nausea and head aches and cramps and back pain is just getting old.