Does Severe Menstrual Cramps In The Coccyx Need Medical Attention?

I am a 55 year old woman with fibromyalgia. Currently I tolerate menstual cramps each month that last about 24 hours and usually involve by left side and left leg. This month the pain centered in my tailbone making all movement except brisk walking painful. Its been 4 days and I still have trouble with sitting and sleeping. Should I go to a doctor. The usual answer to somethin like this is "that's interesting."