text: question about menstruation? i worked in cramped office with three women who, after working together for close to a year, began to get their "cycles" at the same time.  is this unusual?  if not, have studies been done of why this happens?  is there some evolutionary advantage to women have their menses at the same time?  i know it was hell for me! actually this is quite common for women who are very close to "sync" and have their menstrual cycles at the same time.  hey, it could be a good thing.  they're all gonna get pms at once, so just bring in chocolate that time of the month and they'll be happy.  *smile*