As periods often do, Beth Harmon’s arrived at a particularly inopportune moment.

In the second episode of “The Queen’s Gambit,” Harmon is well on her way to winning the Kentucky State Chess Championship when she feels a sharp cramp in her lower abdomen. She runs to the bathroom, clutching her stomach, blood streaming down her leg.

It’s her first time.

Of course it is: Despite its ubiquity off-screen — a monthly occurrence, experienced by half the population for a good portion of their lives — menstruation rarely appears in pop culture. When it does, it’s almost always a “drama,” said Elizabeth Yuko, who wrote about periods in pop culture in the book “Period:” People on screen are either missing their periods — worried about pregnancy or menopause — or, more often, they are experiencing their first one ever.

“We just don’t see normal periods,” Yuko said. “We’re okay with milestones, but we don’t want to hear about everyday, run-of-the-mill menstruation.”

The first period has become a standard trope in pop culture. There are too many examples of scared and confused adolescents to name: Rudy in “The Cosby Show,” Anne in “Anne with an E,” Sally in “Mad Men,” Vada in “My Girl.” In the iconic 1976 film “Carrie,” the main character gets her period — then immediately acquires telekinetic powers.

It’s not surprising that this particular life event would get so much screen time, said Jennifer Weiss-Wolf, co-founder of Period Equity, an organization dedicated to making menstrual products more accessible. The experience — sprinting to the bathroom, hiding the giant red stain on your pants — is easy to dramatize. There is also a deeper cultural significance to the first period that plays well on television, Weiss-Wolf said. A person’s first period is a “cultural, religious and social milestone,” she said, marking an important bodily shift.

The first period is an easy — and, sometimes, “lazy” — way to signal that a character is growing up, said Elana Levine, a professor of media and cinema at the University of Wisconsin at Milwaukee. The period scene in “The Queen’s Gambit” was used this way, she said. Harmon gets her period immediately after flirting with Townes, her first crush. The events, especially taken together, seem designed to convey an official transition into womanhood.

This trope can be frustrating for viewers, said Levine, many of whom don’t experience their first period as a deeply significant life event. There are other moments that do far more to mark the passage into adulthood — but none that are so simple and so pervasive, said Levine.

“It seems like a pretty limited way of understanding a girl’s development and growth. This one thing that often has little significance on your experience of the world more broadly is given all this narrative significance,” Levine said.

“It always strikes me how profound people think first periods are,” Weiss-Wolf said. “We have an entire lifetime with our bodies and menstruation that is so much more rich than that.”

Periods have become far more mainstream in recent years, Weiss-Wolf said. Women-centered blogs, websites and magazines are publishing more on the topic than ever before, she said. Public figures have also been more open to discussing menstruation. At the 2016 Olympics, Chinese swimmer Fu Yuanhui discussed how her period makes it harder to compete. London marathon runner Kiran Gandhi went viral in 2015 for publicizing her decision to “bleed freely and just run.”

Both were celebrated for their candor on a taboo subject.

Companies that produce pads and tampons have also become more “honest” in their advertising, Weiss-Wolf said. While ads used to use blue liquid to show absorption, some now use red liquid that resembles menstrual blood. There has been a similar shift in TV and movies, Yuko said. More producers and directors have been opting to show blood in scenes about periods.

While there’s been a lot of progress, menstruation is still a deeply uncomfortable subject for many, Yuko said. There is widespread stigma and “disgust,” she said, which might make producers wary of dwelling too much on the topic. The first period is safer territory, because the characters often respond negatively to menstruation: It’s something to fear or worry about, rather than something “normal.”

“People are really uncomfortable with biological processes that happen to people with a uterus,” Yuko said.

Some blame male writers, directors and producers, who still dominate the television and film industries.

That’s part of the problem, Levine said. Though some men are certainly able to write scenes about periods with empathy and understanding, she says, a wider array of voices will always create content that is “more sensitive and more aware.”

Television and movies could play a key role in destigmatizing periods “once and for all,” Weiss-Wolf said. When you watch someone’s daily experience with their period — dealing with cramps, noticing changes in their flow — it makes the whole thing much more “normal,” she added.

“It doesn’t have to be the punchline, or the whole story line.”

She would like to see periods portrayed as a regular part of life, she said — because they are.

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