How interesting! "women who are on the pill to regulate their periods aren't actually regulating them. They are suppressing them and replacing them with withdrawal bleeding, and benefits of menstrual suppression accrue whether the monthly bleeding occurs or not. For two generations, women using hormonal contraceptives have bled monthly for cultural reasons, most without knowing there were alternatives."  Follow the link to learn more:

http://jezebel.com/5928316/a-brief-history-of-your-period-and-why-you-dont-have-to-have-it?comment=51209476