Marina coil problems?

[Cjs93]

Hi guys, i had lap surgery to remove endo and have the marina coil placed back in early December, i have quite bad period type pains during exercise and almost constant lower back pain, this started before my surgery but has gotten worse since the coil was placed, has anyone had any problems with their coil? Ive been back to the gynaecologist and they insist the coil shouldnt cause any problems. They said that all of my pain should have gone since the operation but it hasn't really changed changed at all