What Are The Side Effects Of Using IUD?

before i got my IUD,5 yrs ago,my mense skip a month or two then i had my IUD it became regular.but since late 2008 or early 2009 i am already having foul smells before and after my mense then mid-year 2009 my mense already last for a month! dec 2009 i had my period,it just ended this early Feb 2010.my mense is not strong like the regular mense but the flow is stronger than a regular discharge.