Uncomfortable, but not too traumatic.

I was thirteen, and I noticed that I wasn't feeling well during P.E. We were supposed to be doing a mile run, but it was all I could do to walk on the inside of the track because I was cramping and otherwise feeling miserable, and not knowing why. After I got back to the locker rooms, I changed and went to the bathroom before my next class, and I noticed some bloody-brownish gunk in my underwear. It took me a few moments to realize what it was (all the girls in the 4th and 5th grade at my elementary school were brought together and told about puberty and periods when I was in 5th grade), but when I did recognize it, I rolled some toilet paper up in my underwear and decided to go to the nurse at lunch, as there was only one class period between then and lunch. Once I got to the nurse's office, she gave me a large pad and called my mother. My mother came and picked me up to take me to my grandmother's for the rest of the day, where I took some aspirin and layed down while she went out to buy me some clean underwear and pads.