When most ten-year-olds are trading stickers or watching cartoons, Milly Watmore was curled up in pain. Her periods began at just ten — years before most girls her age — and changed everything about her childhood.

“I was terrified to stand up in class,” Milly remembers. “I worried I’d leaked through my clothes.” Her story reflects a growing concern: girls are starting their periods younger than ever. Experts say rising childhood obesity, stress, and hormone-disrupting chemicals in plastics and food may all play a part.

Doctors warn that early menstruation can bring emotional strain and long-term health risks, from anxiety to heart disease. “It can be traumatic,” said Dr. Tania Adib. “Nine-year-olds simply aren’t ready for these changes.”

With the help of her mother and medication, Milly eventually learned to manage the heavy bleeding. Still, she hopes more parents and schools will talk openly about it.

“Periods shouldn’t be a secret,” she says softly. “The earlier we talk, the easier it is to cope.”

Because sometimes, the hardest lessons of growing up come far too soon.