Hi @skylarfox
I am not a doctor and unfortunately I have the opposite problem from you in terms of my weight. I have always had to work on keeping my weight down. It sounds like your infrequent periods are likely due to your weight and perhaps low body fat. Often times women who are professional athletes, runners, etc. with very low body fat have infrequent periods. I am thinking this might be the case for you--not that you are a professional athlete, but just that for whatever reason you have very low body fat. I recall having a number of friends in my younger days who had infrequent periods and they were all people who were extremely thin or who worked out to excess, etc. I think your problem might be helped with some nutritional advice. If I were you and I had ruled out the basic medical issues which sounds like you have, I would try to find a really good nutritionist or someone specializing in women's health and nutrition. It is likely that you can get some advice on healthy ways to put on a little weight as well as to give your body a little help in keeping your body fat to a little higher level. While most women might think "why is she complaining about being thin and not having periods?", it sounds like this is really bothering you. When I was in my 20's (I turn 63 in a few weeks) I had some times when I rarely had a period and I was bothered by it as well. My doctor told me that there was no problem with not having periods and that once I got off of the birth control pills, my periods would return. She was exactly right. But it does not sound like this is the problem for you since you are not using birth control pills now. So I would really encourage you to check out the nutritional/body fat aspect of this and see if you can't get some answers there. Just to put you at ease, I have a really good friend who is pencil thin and does yoga constantly. She is very high energy and is always going, going, going. Her body fat is very low and she has two beautiful healthy children. Sounds just like you so I would not worry too much but I would get some nutritional advice or talk to someone specializing in women's health and nutrition. Best of luck to you and keep us posted on what you find. I have found Mayo Clinic Connect to be an excellent resource and to be full of really caring people.