Ralph Waldo Emerson (1803-1882), perhaps best known for his essay Self-Reliance (1841), was one of America's most influential thinkers and writers. After graduating from Harvard Divinity School, he followed nine generations of his family into the ministry but practiced for only a few years.
The first menstrual period is called  menarche .. The menstrual cycle is about four weeks long, starting on the first day of bleeding and ending when the next period begins. However, it can vary greatly when a girl first starts her period. It may skip months or come several times per month in the beginning.
How Long Periods Should Last Most girls get their first period when they are 12 or 13, though everyone's different and you don't need to worry unless you still didn't get your period by age 16. When your first period arrives, it is most likely to last between two and seven days. [1, 2] As your menstrual cycle becomes more regular over time, the duration of your flow will also settle into a predictable pattern, and most women experience menstrual flow that lasts between three and five days. Some women will menstruate for only two days or up to seven days .