Period query for Mirena users!?
Answers: How long enjoy you had the Mirena? Women tend to enjoy more cramping and spotting during the first few months, but this usually goes away beside time. Your periods may stop altogether by the wind up of the first year of use.
"MIRENA can alter the bleeding pattern. During the first three to six months of MIRENA use the number of bleeding and spotting days may be increased and bleeding pattern may be irregular. Thereafter the number of bleeding and spotting days usually decreases."
-- http://www.rxlist.com/cgi/generic/mirena...
If you've have the IUD for a while, and this has suddenly started up, you may want to see your doctor to rule out a health problem. Otherwise, confer your body time to get used to the IUD. If irregular bleeding turns out to be a long-term problem for you beside the Mirena, you could have it removed.