Question about amenorrhea?

Let me tell you something, from my own experience, unless your weight is in normal range or in the range that is normal for you you are not going to have your periods. In turn, not having your periods is because of not ovulating. You have to have a certain amount of fat for your body to produce sufficient amount of hormones that a woman's body would need to conceive and, even more importantly, to sustain pregnancy. I know it sounds discouraging,but that's what I've been dealing with these past few years.

Although I am not really underweight anymore, I still don't have periods yet. It takes time. So, try to make choices for your future, I know it's hard, but I always ask myself a question " Would I better be slim and childless or healthy (meaning not underweight and not overweight) but be able to enjoy motherhood in the future?". I know it's easier said than done, but that's where you start from. Good luck! You are not alone with this.

No it's not possible. If the amenorrhea is caused by your anorexia then it will have suppressed ovulation. However, it wouldn't be a reliable birth control method because you can't ever tell when your periods (and fertility) will return.