Jessica Biel was 'really freaked out' when she got her first period at 11 — so she wrote a book to help other kids

Jessica Biel wants to get people talking about periods. Her new book, A Kids Book About Periods, which comes out today, aims to help parents kick off that sometimes awkward but important conversation with their kids so they can understand how their bodies work, while also normalizing talking about a topic that's often considered taboo: menstruation. Biel was inspired to write the book — created in collaboration with Period, a global nonprofit focused on advocacy and education — because the 42-year-old says she has “genuine questions still” about her own period and that “all my girlfriends are saying the same thing,” the actress tells Yahoo Life. “Nobody knows anything. And we’re all just riding by the seat of our pants.”

Along with helping to educate people about menstruation through her book, Biel hopes to stop period shame — something she has experienced herself. When asked if she still feels the need to hide tampons up her sleeve like many women do when heading to a public bathroom, she admits, “100% yes. I do. I feel almost ashamed to say it out loud that I do. It’s a complex, deeply layered, profound, learned behavior. How many times have I slipped it in my sleeve?”

But now, she says, “I’m trying to work really hard on saying, ‘I need to change my tampon,’ open my bag and confidently walk to the bathroom, head held high. I’m trying to make a concerted effort to do that. But that little girl inside of me still gets nervous about what somebody’s going to say or see or make a comment about. Or make you feel you might smell funny or you’re gross now because this is happening to you. It’s still in me.”

Those feelings of fear and shame hearken back to when Biel got her first period at 11 years old, the morning she was set to perform in a school play. It’s a story she’s shared on her Instagram. “I was scared,” she recalls. “I thought I was dying. What’s going on here? I was really freaked out.” Biel says that she recently asked her mom if they ever had the period talk when she was young to help prepare her. Her mom confirmed that they had, but Biel says she doesn’t remember it. “I must have been ashamed already,” she says. “And so embarrassed. I’m sure I was so freaked out I couldn't hear her.”

As a mom herself, Biel has thought about how to broach the conversation about periods with her own kids, in particular her 9-year-old son. It’s something that also served as motivation for her to write the book. “I have young boys — how am I going to talk to them about this?” she says. “I don’t want the same feeling that I felt when I was younger, which was like boys thought you were just gross and weird, or anyone who didn’t have a period would make fun of you and it was shameful.”

For Biel, it’s important for her sons to know about menstruation even though it doesn’t impact them directly. “If they don’t have that information, they will not be able to respond compassionately,” she says, adding: “I want my boys to have a language around it. I want them to be included in the conversation.”

Biel encourages parents to use her book as a tool to start having these candid talks about periods with their children. “We don’t want you to just hand the book to your kids,” she says. “The idea is to sit and open the book together. It’s the first step down the path of: Here’s just the real information and maybe you’ll be inspired to find more resources, or your kids will ask more questions and you can find answers together.” She adds that while families have to pick the time that’s right for them to have these conversations, “I think we don’t really give our young people enough credit about what they can really handle.”

In looking back, Biel wishes her younger self had known that there’s a range of what’s considered normal when it comes to menstrual cycles. “Your period can come and then it can go,” she says. “My period came when I was 11 and then it didn't come again for a year. All of these different things that happen to different people’s cycles is normal, and it’s OK. Knowing that it’s not just going to be like clockwork every month, I think it would have helped make it less shameful.”

Biel wants to get the message across to young readers that “you can do anything on your period. If that’s what makes you feel good in that moment, do it,” she says. “You are capable no matter what. But also, if you feel like you want to stay at home today and rest and watch a movie and hang out, it's OK to do that, too.”