there's our catastrophe

No 2: really?! Oooo-errrrrr

yep!  this really pisses people off.  sorry everyone, if you believe there is a spiritual or metaphysical connection between the moon and your cycle that’s a personal matter, but if you believe there is a literal physical effect akin to the tides then that is factually incorrect because: 

1.  PHYSICS. the moon has only been demonstrated to have a measurable effect on very large bodies of water; do you see the water creeping out of your glass every high tide?   also, tides are caused by a number of other factors (such as the sun’s gravitational force and the earth’s rotation) in addition to the moon’s gravitational force.  moreover, all things exert gravitational force, not just astronomical bodies.  The gravitational attraction between two bodies is determined not just by the mass of each but also by their relative proximity.  in other words, the K-mart down the street brings more gravitational force to bear on your uterus than the moon does.  but I guess that’s less romantic and witchy. 

2.  TIMING. the cycle of the moon is extremely regular and precise, while menstrual cycles are notoriously irregular and personal.  if the moon affected menstruation, most people would bleed at the same time every 27.3 days, barring health problems and similar.  this is clearly not the case. 

3.  ANTHROPOMORPHISM.  all placental mammals experience estrous cycles, most of which do not happen on the roughly-once-a-month basis experienced by the majority of menstruating humans. 

in short: the fact that human menstrual cycles have a timeline slightly similar to the time it takes for the moon to orbit the earth is pretty much just a coincidence.  I know, I wanted to believe too.