Could someone explain what it could have been?

that's...traumatic..but as long as your ok

I completely forgot it happened, until my brother mentioned something about periods, then i made a joke about the time I had my "first period", and then explained that story.

lmaoooo

Kidney stones can do that, but they're not that common for kids. Tell your doctor next time you go if you haven't already, find out if you have a family history of stones.

Bro go to the f**king hospital