Mirena IUD

So I had my IUD for about 9 months now. Is it normal to spot on and off up until my period and then once my period is over I have like a week or half to no spotting/cramps then I’m back to spotting and cramping on and off again. With my period following shortly after? I can feel the strings but I’m having some belly pain when I breathe out the pain occurs next to my belly button. It’s not severe but sort of dull. Is that related somehow?