Burn more calories during menstruation?

Today I did not go to the gym at all. Eeekk! Its hard, but I think I can manage. With all of that free time I did manage to research a pretty interesting topic: Menstruation. Last night my girlfriend and I were talking and she seemed to think that women burned more calories during their period. A very convenient fact this would be. Most women like to consume chocolate and that would be a perfect explanation as to why. Their bodies are requiring more calories. While I did not really buy into it, I decided that research was in order. Here are my findings (in plain english!):

1. Basal metabolic rate (how many calories that are burned while at complete rest) does change throughout the menstrual cycle.
2. A majority of women burn more calories in the weeks leading up to menstruation.
-BMR hits a low in early follicular phase (end of "period)
-BMR hits a high in late lenticular (right before "period")
3. Some women do not show significant variations in BMR throughout menstruation.
4. The period of decreased metabolism is similar in magnitude to the subsequent increase in metabolism.
5. Average basal metabolic rate for women was 9.4 calories per pound of body weight. (remember this doesn't take into account ANY activity.)

Next time I have some free time I'll research the whole chocolate aspect of things.

References:
1. Henry, Jaya et al. (2003) British Journal of Nurtition 89, 811-817
2. Solomon, Susan et al. (1982) American Journal of Clinical Nurtition 36, 611-616
1. Author (year)Journal edition, pages