When i was 15 i got my menarche and i have had about 20 periods since then but my problem is that im turning 20 in August and I have gotten so few periods. The only time i get my period is when i start losing a lot of weight and my period normally last about a month and/or over when i get it. I don't know what is wrong With my reproductive organs. Has this happened to anyone else before? Does anyone know what is happening? Will i become infertile from this or is there something seriously wrong with my ovaries.