Pregnant with IUD?!

Okay so I got my IUD back in November of 2013... Been with my boyfriend since May 2013. But here's my question well story. We been having unprotected sex since forever (3years) and I use this app to keep track of my period which I still get with the IUD, but I'm 68 days late (thanks app for counting a reminding me everyday) I'm kinda scared to be pregnant and have the IUD. Is that even possible? I'm a very skinny person and you could tell even if I put on alittle weight and I have what looks like the start of a baby bump. Any help!? And yes I'm over the age of 18.