And it's not just a joke either. From a paper entitled
MENSTRUATION AND AGGRESSIVE BEHAVIOR IN A CORRECTIONAL CENTER FOR WOMEN 
Of all violent crimes committed by women in Paris in a given year, Cooke notes that 84.0% were committed by women who were menstruating. In a New York prison for women, Morton found that of the forty-two inmates convicted for violent crimes, twenty-six commited those crimes during the pre-menstrual week.
This is something to keep in mind in case you're wondering if perhaps it's not the best time to crush a shit test. The science would tend to indicate dialing down the conflict rather than ratcheting it up is wise, considering that women are
about 360 percent more inclined to violence at the peak of their cycle than they normally are.
