
Eating Disorders Support Group
Eating disorders are marked by an obsessive need to control the intake and/or purging of food. This community is dedicated to those struggling on the road to recovery. Join to discuss your experience with others and find support. Get advice, ask questions, and meet others who are going through similar struggles.
BMI isn't foolproof, it is just a guideline. It doesn't take into account muscle mass, etc..
Loss of your period is caused by lack of enough body fat to stimulate hormones, by too much exercise, too much stress, etc.. A lot of things cause it.
If you get to the point where you stop having it for three months or more, you need to see a doctor/gynecologist - whether or not you are currently willing to seek help for your eating disorder. The longer you go without your period, the higher the risk for infertility and osteoporosis (estrogen helps absorb calcium into the bones).
I would agree with Katie, def. keep it up a bit so that your body can heal and regulate.
Good luck :)