New parents Jessica Biel and Justin Timberlake can be confident about one thing: their son, Silas Randall, whom they welcomed in April, is quite possibly the cutest baby to ever exist.

But Biel wasn’t quite as self-assured during her journey through pregnancy. In the latest issue of Glamour magazine, the actress opened up about the moment she realized she didn’t quite understand how her body works. She was 31, had recently decided with Timberlake that they were ready for a baby, and was hella confused.

“I’ve been on the Pill for so long; how hard will it be to get pregnant?” she remembers thinking at the time. “Suddenly I realized I really didn’t know what’s going on inside my own body. It was shocking.”

Now, Biel is doing her part to help other women understand the many details and intricacies of their bodies and reproductive systems. She’s teamed up with activist Saundra Pelletier, the founder of nonprofit health care organization WomanCareGlobal, to launch an educational video series that covers topics like puberty, contraception, menstruation and STDs.

"More than half of our nation's pregnancies are unplanned, and just 22 states require public schools to teach sex education," Pelletier told Glamour. "Jessica and I realized we can help change this.”

“We want girls to know what their [body is going through] so they don't feel scared or ashamed or gross,” Biel added, saying they plan to "share girl stories, fears, and insecurities” in a tone that’s “informative but also goofy, smart, witty.”

The series launches Sept. 28 and can be seen at womancareglobal.org.

For more information about sexual health and birth control, visit It's Your Sex Life.