Here's an interesting excerpt I found regarding pain and estrogen in a book regarding fibro:
Researchers at the University of Michigan have found that women are better able to tolerate pain when estrogen levels are high by releasing endorphins that soften the signals. Unfortunately, a dip in estrogen, which occurs just before your period, reduces the symptom's effectiveness, which may explain why women say their FMS symptoms are worse during their periods.
: I wonder if this is why pregnant women and mothers of newborns often experience a remission in fibro symptoms. We should all get regular shots of estrogen.