oki doki. i'm 15 years old and iv been havin my periods since i was about 11. they were ovisly irregular at first for about a year or so and ever since have been regular. However, i have missed two periods in a row and possibly this third one now. I have not been taking any medicines,not doing excessive exercise,no change in diet, not under extra stress either, just the usual routines. I am not sexually active either, never been with a guy so i have no idea on whats wrong. I dont have any symptoms or anything that may suggest something. I just hope im not infertile or anything. COULD YOU PLEASE TELL ME WHAT MIGHT BE WRONG OR WHAT I SHOULD DO????