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.
The good news is that menstruation usually normalizes after about two years. Normal menstruation can last from one to eight days. For most women with regular menstrual cycles, their period will last for three to five days. That doesn't mean that anything is wrong if your period is longer or shorter.