Im 23 yrs old. I have irregular periods, which consist of no period for 6 months during the late spring early summer season. Then when it does come it lasts between 5-7 days, which is normal for me. Afterward my period does not come for 2-4 months. This started after my Senior year in HS, 2006. I thought maybe because of sports it shortened it and at that time I was sexually inactive. At the age of 21 I lost my virginity, but my period followed this same pattern. I would get my period and then it would stop for 2-4 months and then it would regulate and then go back to irregular. I feel like my period is all over the board here and I want to know why. Stress and lack of exercise might be the issue here, but i'm not that heavy weight wise. There has to be something more to this, I just dont know what.