well... it could be your period coming. Some women experience PMS symptoms before their period actually comes for the first time. If your period has already come for the first time, and you are due, you may just be experiencing PMS for an extended period of time, or even skipping your flow all together, which is completely normal for someone your age. I wouldn't freak out over it, but if this condition continues for an extended period of time (or keep reoccurring with no flow), and you are worried, the best thing to do is go see your GYN.
Bottom line, you shouldn't worry. You're still young & irregular menstrual cycles are normal at your age.
Good luck sweetie!
