Is my birth control still effective??

Hey everyone! I have the SKYLA IUD. I’m due to have it taken out this coming May. The doctors made me aware that it might take a few months of me having it in for my periods to start to subside and eventually disappear. My periods went away IMMEDIATELY. I haven’t had one since May 2016. All of a sudden January 10th, I started. I’m actually bleeding regularly, along with cramps and everything. Is it possible that the horomones on my IUD are running out? Am I still protected? Should I start using backup BC?? HELP