Mirana IUD question...

So I have the Mirana IUD now for little over a year. I haven't had my period for a while now. like I had it for the first 3 months after getting the IUD inserted but then my period became lighter until it just became spotting every 28 days. and this month I've been getting the exact same pregnancy symptoms (flu/fever at first, always tired and out of breath, and no sex driver) i had when I was pregnant with both of my kids. so I talked to my friend and she thinks I'm pregnant. what are your thoughts should I buy a test or have any of you with an IUD experiences this too and not be pregnant.