mid-cycle cramps

I get cramps in between periods. I get them almost everyday at least once, until after I have my period... then I get about a week break with no cramps. The cramps seem to alternate between both of my ovaries each month, but sometimes both sides hurt. I've had an ultrasound done, but everything looked normal. My doctor suggested I remove my iud if it becomes too bothersome, just incase it's the cause of the cramps.