Hello. I am an 18 year old female and have menstrual problems. I first had my period at 15 and it s always been very irregular. But in the past two years I don t think I ve had one. I m not sexually active and I weigh 118 pounds at 5 6. I ve lost about 10 pounds in the past year because of healthy eating and exercise (twice a week) but I think I do have low fat levels. I m fairly worried, does this sound abnormal to to you?