Amy Schumer Discusses Stigma Around Menstruation, Why She 'Didn't Have Period Shame' Growing Up

Amy Schumer is committed to being everyone's "older sister" when it comes to period talk.

The comedian and Expecting Amy star, 39, is teaming up with Tampax in an effort to "normalize women having their periods and take away the stigma," telling PEOPLE she was "so excited" for the partnership, as it felt "incredibly natural" and "almost felt too perfect to me, because we have the exact same goals in mind."

"We want to ... just take the shame away from this thing that is really strange that it's still so secretive and that we're made to feel bad about it," says Schumer. "And just to get rid of some of the myths."

Among the "misinformation out there about periods" that the I Feel Pretty actress has seen over the years is the myth that "using a tampon means [women will] lose their virginity."

"[Women and girls] have all these misconceptions and fears, and there really isn't that much education out there," she says. "Only 24 states have any sort of required sex education and only 13 of those states require any sort of upkeep of actual medical studies. So if you don't have an older sister, or if your mom isn't super up to date, you really have no one to rely on. So I'm hopefully gonna be people's older sister, explaining the things that I've learned to them."

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While Schumer doesn't "totally remember" her first conversation about menstruation with her own mother, she admits that a fifth-grade lesson when someone came into her classroom "with a model of a vagina" was something that "scared the s— out of" herself and her fellow students, and she didn't learn much as a result.

"I do remember that my mom made me feel informed, but she never taught me how to [insert] a tampon," the star tells PEOPLE. "I didn't find out how to put a Tampax in for probably a couple of years. People don't understand — I didn't understand that your flow changes and you need different sizes so I think I was probably just using whatever tampon my mom had. If it hurts when you put it in, you go a size down."

"I didn't know that. And I didn't know how far to push it in," she continues. "Some women don't even know — they're not pushing it in far enough, so they can feel it. You shouldn't feel your tampon. And those are things I didn't learn for far too long."

Schumer shares that aside from having similar goals as Tampax in educating girls and women about their periods, she was inspired to partner up with them because there are "woman at the helm" of the company — which checks her box for "a diverse and equal team running it."

"Because it's not just the white men running the company; there are more voices than that. So they're actually fighting for what women want," says the Trainwreck star.

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As for how she handled her own cycle as an adolescent, Schumer says she "didn't have period shame," explaining that is what the Tampax campaign "is about," at the end of the day: "Women have periods — that's how we're all alive, is that we get our periods. And then we don't. We have to continue the human race, but we don't talk about it."

"I didn't even know to be ashamed of it, so I would raise my hand and say, 'Can I go to the bathroom?' And if my teacher said no, I would say, 'I have to change my tampon or my pad. I have my period.' " she recalls. "Then everyone would giggle and the teacher would be so embarrassed, and that's kind of how I learned, 'Oh, you're supposed to be ashamed of this.' But I would say, 'I have my period' like I would ask someone what time it is; it was very normalized to me. And I hope that's what we're working toward."

Schumer also reveals that she chose to be honest about her bodily changes after giving birth to son Gene David in May 2019 for transparency's sake, saying it was "just as much for me as the idea that it can help anyone."

"For me to post a picture in my postpartum underwear and have an overwhelming number of women say, 'Oh my God, I remember those' — it's such a specific time and memory. It really connects us and is this thing I think people haven't spoken about very much," she says. "Maybe we haven't been in this position both with social media and a time where women are learning to stop apologizing for things they shouldn't apologize for."

"My friends will even text me after seeing posts, just like, 'Oh, I remember it was so hard,' " Schumer adds. "It's just really helpful to connect with other people on there."