So, this is personal, but what better place to ask, right? I've been on birth control for the last 10 years, never missed a 'period.' I've stepped up my exercising and dieting in the last month or 2, and this month the period was not there! I used to work with women with ED problems, and I know this is common if you don't eat enough. But I definitely am eating enough. I run 5-7 miles 6 days a week, and eat about 1500 NET calories a day. And I am not pregnant. Any thoughts?