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.
1 The average menstrual cycle lasts 23-35 days (counting from the first day of one period to the next). 2  Some women may not have a regular cycle (number of days between periods). 3  This is normal, especially in the first 2 years after a woman's first period. 4  Most women have their period for about 6 days. This is normal, especially in the first 2 years after a woman's first period. 2  Most women have their period for about 6 days. 3  Some may have it fewer than 6 days and some may have it for more than 6 days.