Well, here is a strange piece of history: A short animated film made by Walt Disney for Kotex, explaining menstruation. The fuck?
I found this little gem (which has been circulating online for years) while browsing Flow: A Cultural History of Menstruation, trying to confirm that Kotex pads really do have their origins in World War I. You see, it's tough selling "feminine care products," because "feminine care products" is the world's vaguest term, and God knows the world might've split open if somebody had gotten more explicit in an advertisement placed in a woman's magazine. One of their tricks was to churn out oh-so-helpful pamphlets and booklets for young women that explained the ongoing changes to their body while peddling Tampax or Kotex or whatever brand. Think of it as pre-Internet sponsored content.
Film Threat (via Mental Floss) says this particular video dates to 1946. Between World War II and Fantasia's bellyflop, Disney was strapped for cash at the time, so they started doing some commercial work. Among them was this ten-minute short for Kotex, which features a bunch of animated women who, yep, look like Disney characters and such advice as: "Once you stop feeling sorry for yourself and take those days in your stride, you'll find it's easier to keep smiling and even tempered." Accompanying the movie was a wonderfully titled handout, "Very Personally Yours," which you can read in full at the Museum of Menstruation. The short helpfully previews the content: "Among other things, the booklet explodes that old taboo against bathing during your period. Not only can you bathe, you should bathe."
And that is how Disney ended up explaining periods.