A female’s first menstrual period, known as menarche, occurs during puberty. Menstruation indicates that the body is mature enough for reproduction. About 98% of girls begin their periods by age 15.

Add Yahoo as a preferred source to see more of our stories on Google. Periods are triggered by a drop in hormone levels in your body, specifically estrogen and progesterone, Dr. Anita Somani, ...

It's not an official medical diagnosis, but rather a form of premenstrual syndrome (PMS). More than 90 percent of people who menstruate say they get symptoms like bloating, moodiness, and headaches a ...

The first few times you get your period, it’s totally normal to feel caught off-guard. (But, ofc, not ideal.) In fact, irregular periods are super common in the beginning. Your body isn’t ovulating ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." The first few times you get your period, it’s totally normal to feel caught off-guard. (But, ofc, not ...