If the IUD was to move and start to grow into you, you would feel it. There are
strings attached to the IUD
for you to be able to check yourself. Your dr will also check during your yearly physical. And.... If it were to move out of place you will feel it. It will cause a serious abdominal pain. Don't get me wrong, it can happen, but with the amount of IUDs used in the US and Canada, I think it is pretty rare.