Boys and babies

So the other day I only had six out of 11 eighth grade girls in class and no boys because of an incident that had occurred during evening study the night before that involved a bunch of them in the computer lab and a flying bottle of lotion...and that's really all of the story that I know. Anyway, the girls who were still in class were working on something at their desks while I was semi-distracted by something at mine.

Dramatic Poop Girl: I hate being on my period! I wish I was a boy! Miss Book, why don't boys have periods?
Me (barely looking up): Boys can't have babies.
Dramatic Poop Girl: Well I can't have a baby either! [which made me actually look at her] My mother would kill me!