The likelihood of a miscarriage in your situation depends on the placement of the iud vs. Placement of the implanted embryo. Only an ultrasound would be able to tell. Obviously, based on the comments above, it is possible to carry a healthy, normal pregnancy. Good luck. Hope it all works out well for you.
I got pregnant with the paragaurd iud but unforturely I delivered my daughter still born at 18 Weeks. But I had to have surgery to remove mine. hopefully everything goes well for you :)
I got pregnant off the paragard iud and had a pretty normal pregnancy. It was def a surprise. I wasn't sure about the pregnancy I was so scared because when I found out I was pregnant I had a 2 year old and 1 year old! But my baby is now 5 weeks old and I wouldn't trade him for anything in the world.
My doctor had an IUD when she got pregnant with her last child. We were actually pregnant at the same time. She had a normal pregnancy and has a healthy nine yr old boy now. :-)
I've never been in your situation, but this was the best article I could find:
http://miscarriage.about.com/od/riskfactors/f/pregnant-with-iud.htm
I wish you luck.