Hello, I Have The Bar In My Arm And Have

Hello, I have the bar in my arm and have had since March last year. I stopped getting periods after a few months and have had no issues. However a few days ago I started getting cramps and thought I might be having a period and just took some pain killers this has now been going on for days (no period) and I now have extremely bad cramps in my lower abdomen and all in my lower back. What is happening?