1) They're icky. Ickier than boys.
2) When you're on your period, keep it more secret than any secret you currently have.
3) People can tell when you're on your period. (See the contradiction there? What's the point of keeping it secret if people can tell?)
4) Every woman turns into a homicidal, man-hating, banshee when she's on her period.
5) We don't want to make out, touch hands, or have our guys within five feet of us when we're on our period.
6) You shouldn't wear white.
7) For the love of all human kind, do not say the actual word "period"!
8) We wish we were born with different parts one week a month.
9) If you use tampons, it means you're no longer a virgin.
10) Periods simply suck and there's nothing we can do about it but pig out and lounge in our pajamjams all day.
11) It is, one hundred percent, Eve's fault that we bear so much pain once a month and during childbirth. (Adam had something to do with it, too. Hehe. And if they didn't bite that forbidden piece of fruit, dang it, their children would have.)
12) Guys don't need to hear about this stuff. Ever.
13) Getting your first period automatically, as if menses was some kind of magical occurrence, makes you a woman.
14) Hide hide HIDE those pads and tampons deep inside your purse so no one can ever see them!
15) When you're old enough to stop getting periods, you lose a part of what it means to be a woman.
All these stone-age beliefs do is hold us back and keep periods a taboo. It's okay to talk about it. It's okay to not act like a wicked witch while you're on it. You're officially a woman when you reach a point in your life when you feel like one, and it doesn't stop when you no longer have your period. Guys should know about this stuff. None of it is anything to be ashamed of. You're a virgin until you have sex. No need to hide your pads or tampons--you wouldn't hide a band aid, would you? You can wear white--just make darn sure you're covered.
Shake it up. Talk about it like you talk about anything else. Educate people. If we do this, sooner or later, young girls getting their first period won't be as mortified as you and I were.