hi...i'm 17, and i have problems with irregular periods also. I'll go for months without having it, then i'll have it for a whole month sometimes. sometimes i'll get it, and then get it two weeks later. It's sooo uncomfortable, and i hate not being prepared. I went to my doctor and got a birth control perscription, now it's heaven! i get it for a couple days, and i know exactly the week i'll get it, and it's light. go ask your doctor!