Chances Of Getting Pregnant While On The IUD??

Melissa
Is it possible? Has this happened to anyone on here? I was suppose to get my period on the 27th according to this App. I just started using it last month. It was accurate then. Im not spotting or anything. No discharge. At first I was cramping a bit but it went away. A little bit of sore boobs. Ive hac the IUD in me for 8 years now. But Ive never been this late.