I got my first period at 14, and between then and now, have lost it several times
for a year or longer. In high school, I was put on Premarin and
a few other pills, none of which had any effect. At 21, I finally began birth control (my mom was very opposed to this for the health risks, which is why I didn't start it sooner). I had a great experience - no side effects, and my periods were finally regular, even while at a lower weight.