What Are The Side Effects Of Using Mirena IUD?

I'm 29 have had the Mirena IUD for about 4.5 years and am planning on having it removed within the next week or so. I've been feeling some sort of hot/burning sensation where I assume that it is. Is this normal for someone reaching the end of the IUD's term? I'm currently not sexually active, so I'm not worried about it being an STD.