Irregular Period?

I've never have sex, so I don't deem I am pregnant. But what's the produce of unsettled period/irregular period? I've have my length for 1 year and partially. I'm 13, I relish sports, i've have a bit more sports more this month (swimming, etc), and my length is sometimes precipitate andsometimes behind schedule. They second around 7 days. And the difference between cycles are 20 something days. It's different. Last 2 length i've have 23 and 21 days, and in a minute it's the 28 sunshine. I still haven't get it. Why is it so irregular? Should I be worried?
Answers:

Stomach cramps after an argument?

It can be because of your low freight, greatly of exercise,(especailly track) or stress. -L Btw, you should weigh AT LEAST 118.Then your extent will straighten itself out. Good luck to you. :)

I deem something is wrong near me, whenever i hold my interval, i hurt sooo impossible i almost throw up.?

probably because you do sports. and also, because you one and only started a year and a partly ago. its irregular when you start. some full-size women still hold irregular period.... purely depends on ur body. i guess

oh, i didnt read that member, wow. your sooooo small. I revulsion you right in a minute...... ugh. jk, but I am so resentful.. im twelve and I weigh 108. dont explain to anyone