By 6th grade, most girls I knew were starting to get their periods. They’d walk from class to the bathroom hiding their tampons and pads up their shirt sleeves, inside their boots, in their waistbands — really anywhere they could be wedged. Not hiding your menstrual supplies was an invitation for vicious bullying.

That year, I remember one boy called a girl “gross” when he realized she had her period. Her cheeks turned red, and she grew silent. It was clear she didn’t know what her next move should be — should she run to the bathroom to hide and cry or just sit at her desk and stay silent? I remember thinking to myself – if she had had a stomachache, no one would have really cared.

So why are periods any different?

As a youth activist, I know the importance of standing up for what’s right and letting the truth be known so future generations don’t share the same burden. People should hear women, and they should hear me now: periods are normal, and it’s past due for them to be treated as such.

Every day, more than 800 million people around the world menstruate. Yet despite how often this occurs, periods are deeply stigmatized. And this stigma has existed for a long time — reinforced by those taking insincerely something that impacts about half of people around the world.

We didn’t just wake up one day and say, “I’m ashamed of my period.” No. We were taught and encouraged to hide the truth of our periods by the world around us. There are teachers, family members and friends who think our periods are disgusting, shameful or embarrassing. Even at the all-girls school I attend now, the shame runs deep. Girls still lie to their teachers when their periods make them sick.

This stigma is perpetuated through social media, in pop culture and even within some cultural norms. In the U.S., it wasn’t until 1985 that the word “period” was said on TV, and even now, the portrayals of periods in most media are inaccurate at best, harmful at worst.

These entrenched displays of stigma tell us that we’re indecent, when periods are simply a normal, bodily function for girls and women across the world. Over time, this feeling of indecency can have severe, negative effects on our mental health, well-being and physical health.

Over the years, I’ve become increasingly comfortable talking about my period and the experiences associated with it. I’m still learning to attack this stigma day by day, but I’ve been privileged enough to have a supportive community around me — people who help me to speak my truth daily and feel unafraid.

Much of my security on the topic starts at home. In my community, there are true role models who show me how to be honest about my pain. They encourage me to be my authentic self, to not hide who I am or what I experience—that women and their bodies have been looked down on enough.

I’ve also received a great deal of encouragement from my mentor, Miss Lisa Brooks of Global G.L.O.W., an organization that mentors girls like me to advocate for ourselves and make our communities stronger. As part of my G.L.O.W. after-school club, we’ve had discussions about how all girls, no matter who they are, what they have or where they come from—have a voice they are capable of using; that despite others trying to put us down, women and girls are indisputably powerful. Lisa has helped me realize that we are all change agents.

So here I am—relaying my experiences to you, moving the needle forward in the hopes that one day, period stigma can be eradicated for girls everywhere.

That girl who I told you about from my 6th grade class? In that moment, the bully made her feel stuck, alone in her self-consciousness and embarrassed by her body. Well I wasn’t going to let her feel that way. I stood up for my friend. I told the bully that periods are normal, that girls aren’t gross. That we’re powerful, passionate and capable — so much more than the ugly stigma he was perpetuating.

Since then, I’ve become an even bigger voice against gendered put-downs, and I’m not afraid to tell anyone that I’m on my period. If you get your period too, join me this Menstrual Hygiene Day — and beyond — in being open, honest and unashamed. Your period is not something that negatively defines your character, your personality or who you will be in the future. It is normal, natural and expected. Your period is something to embrace, not something to hide. You are beautiful, strong and powerful, and no one should tell you otherwise.

If you don’t menstruate, you can still support those in your life that do. If you can, bring tampons and pads with you to school so if your menstruating friends forget supplies, you’ll be there for them. Dispel the idea that period blood is gross and remind yourself that cramps are just as natural as any other pain people experience.

More than anything, stand up for us when we are being bullied. I’m tired of girls being the only ones to fight. Shut down hate when you hear it.

I may continue to face discrimination for things outside of my control, including my menstrual cycle. But if we all continue to stand up and push back against this discrimination, we can exist in a future where women and girls can be honest about the struggles we face and achieve our full potentials.

I will not stop speaking up about period stigma until it is erased. And whoever you are, reading this, neither should you.