I, too have had flares and surplus symptoms of fibromyalgia around my cycle. Well, seeing as that my cycle is not exactly normal anyway (up to 21 days of menstruation followed by yet another cycle as early as 3 to 4 days following) it's hard to tell. However, with the added hormones, lack of iron, and stress alongside menstruation, it is my assumtion that flares would be a natural part of the life of a menstruating woman. When I am overly stressed, fatigued, or have lack of control of my thyroid (which also causes hormone problems) a flare is short in coming. I, until just recently, had not even pieced it together that flares and periods would coexist. I did know that lupus could have an effect on one's cycle, but it had never occured to me that it could be the other way around, as well!