thanks for using health care magic
One of the side effects of mirena
is cramping which is tolerated to an extend beyond it is removed.
However, the pain you describe warrants that an in dept investigation be done to rule out more severe complications such as embedding of the device into or perforation of the uterine wall or infections.
That will require that you do an ultrasound
to see the orientation of the device.
If there are any complications appropriate measures shall be taken, for instance, if there is a perforation, surgery will be done, if there is embedding, the device could be remove etc. However, even in the absence of visible lesions, if no other cause is obtained and the pains are unbearable, you doctor may consider to remove the device.