I first came across the word "period" when I was reading the Sweet Valley High book Jessica’s Secret.I’d never heard of a period before — in a health sense. It was my dad, a physiologist, who took it upon himself to explain what it was. When I eventually got my first period in the midst of technology class, I didn’t think I was dying, despite the bloody mess on the back of my skirt. I was prepared, thanks to my dad — and the Sweet Valley Twins.Yet, in many low-income countries, the word "period" is not up for discussion. So, when girls start menstruating for the first time, they don’t know what to do — many don’t even know what’s happening to them.According to a United Nations study , one out of three girls in South Asia knew nothing about menstruation prior to getting their first period. International nonprofit WaterAid estimates that 48% of girls in Iran and 10% of girls in India believe menstruation is a disease.A lack of knowledge, coupled with harsh conditions, mean girls and women face serious challenges when it comes to managing their periods.Why? Many girls around the world still lack access to affordable hygienic menstrual products. Instead, they use improvised materials, such as rags or leaves, which are uncomfortable and can lead to leaks and infections. Girls also lack access to clean, safe private toilets. There is no clean water within or near toilets, which means it’s hard to clean up and discreetly dispose of used menstrual products.Confined indoors for seven days and banned from using salt in food, women and girls often face harsh social taboos about menstruation, which excludes them from activities,such as cooking or praying — and even going to school.Many young girls are forced to skip school during their period , because of embarrassment or lack of access to working, private washrooms. Others drop out altogether. Stopping school at an early age leaves them vulnerable to early marriage, violence, and forced sexual relations. To improve health and increase school attendance of girls, Plan International , a child-rights organisation, and its Because I am a Girl campaign is addressing the social beliefs and norms that cause stigma and social shaming when it comes to menstruation.From distributing hygiene kits to girls affected by disasters to constructing child-friendly toilets in schools across Asia and Africa, Plan International is working with communities to break the taboos surrounding menstruation. Together with local governments and schools, the organisation is training district health workers, teachers, and volunteers about the topic, as well as holding community theatre shows and hosting radio shows on the topic so girls can talk openly about menstruation.Ahead, nine girls from around the world bravely open up about their first period. Why? Because menstruation matters to every girl. Period.