The GOOD news about the IUD is that it should
last you until 2018 if all goes well. The insertion can be unpleasant, unfortunately. If you were my patient, I would advise you to try Aleve and if that doesn't work, you may wish to call your provider because, he/she may be able to give you a mild narcotic pain reliever to get you through the first few days until the cramping is more bareable.
ALSO--if the pain continues beyond a few days, you may want to request an ultrasound to be certain that the IUD is located properly in the uterus