I was... 12? Yes, that's about it.
(Also, I was about 80 pounds when I started, so I'm either unlucky, or that "The fatter you are, the sooner you start your period." isn't true. Also, I'm very short for my age, so that might be a factor. I'm 4 foot 8. Yes, I know. I'm short.)
I think it was about November 7th.
I had already got that brown colored stuff in my panties, but I never got the blood. About 2 months later, I was changing my panties, and I just happened to look down, and there it was.
A huge blood stain. I was like, "Ohhhhh s**t." I freaked out, but I calmed myself, and went into the bathroom calmly. I stuffed some toilet paper down there, and life was good. I never told my Mom until a month later, when it decided to become regular. :B
For extra fun, I'll tell you how I told my Mom:
Me: Hey, Mum...
Mom: Yes? (She was wrapping Christmas presents)
Me: You know those things... At the end of sentences... What are those called again?
Mom: Periods?
Me: Yeahhhh... About that... I started mine.
And then she taught me how to use pads. She had these cute little pads that fit my panties just right for some reason. <3