I am 24 now but when I was 11 I started my period, it lasted only a week and didn't come back untill exactly a year later. but when it came back, it come for a week then go away for a week, come back for a few days go off few days, and over and over again thats how it was. one month I had my period for a whole month...being so young I was too scared to even tell my mom I had started, (I have a mom and an older sister so it was easy to manage the flow if you know what I mean) after months and months went by it went from randomness, to 3 weeks on and 1 week off...finally, when I was 14, my mother took me to the doctor and I was put on birth control for a hormone problem. Doesnt mean something is wrong with you and its harder to meet someone at my age that didnt have simillar issues. It fixed everything! Made me so sick though bc I didnt understand to take it with a meal and take it at the same time every day, so make sure you do..seriously...also, I would recomend you finding a female gyno with a sono machine in office to check for any cyst without having to pay for it,(theres alot of them and its the same price as any other, look at the ones connected to a hospital if you can) your kinda young so I can see why you would feel uncomfy talking about it, but if you just say the words, "mom I want an appointment with a female gyno bc I'm having irregular periods" I can almost promise it will happen in a snap. I hope this makes you feel better, and go see your gyno!!