So in devouring all of my lunch and afternoon snacks by 11:35, and realizing that I've been extra hungry the last two days, I decided to waste some time at work doing a bit of googling.
According to nutritionist Mary Hartley:
"A woman’s basal metabolic rate rises by 5 to 10 percent during the week before the onset of menstruation. That would amount to burning 75 to 150 extra calories a day for a woman whose metabolic output measured 1500 calories. The metabolic rate returns to normal, or slightly less than normal, on the first or second day of menstruation. Every woman has a cyclical metabolic rate but the timing of the rise and fall is not identical for every women."
And, an article
http://www.livestrong.com/article/295115-calories-burned-while-on-your-period/
I also have to jokingly wonder if the author of the article simply didn't want to piss off a bunch of pms-ing women (300 extra calories?)