For a girl getting her period is probably the biggest event in puberty.
Menstruation is a normal healthy part of being a young girl or woman.
For the most part menstruation starts between the ages of 12 and 13.
Below I will try and help you understand the woman's cycle a little better.
The menstrual period is just one part of the menstrual cycle.
It's a 28 day long process that happens to all women who have not yet reached menopause.
The cycle involves all parts of the women's reproductive system.
This includes the uterus, cervix, ovaries, fallopian tubes and vagina.
The menstrual cycle is the body's way of preparing women for pregnancy.
This cycle usually lasts around 28 days but in some cases can be as long as 35 days.
Each and every month the reproductive system prepares for the fertilization of a woman's eggs and the development of a fetus.
The process is conducted by hormones, mainly by estrogen, progesterone, follicle-stimulating hormone and luteinizing hormone.
To make this as easy as possible the menstrual cycle has four phases.
The first phase is menstruation.
Each month the uterus has to prepare itself for an embryo by thickening its lining with tissue and blood.
When an egg is released with out being fertilized, then the uterus will shed this lining through the small opening of the cervix and passes out of the body through the vagina.
The menstrual flow is made up of blood, mucus, and body cells.
The flow is usually red or almost so dark that it's black.
It can include clumps or clots.
Periods usually last between 3 to 5 days.
The second phase is pre ovulation.
This occurs when the period ends.
It is now that the ovaries start preparing to make another egg, or ovum, to be released into the fallopian tubes.
Ovulation is the third phase.
This is when the egg is released from the ovary into the fallopian tubes.
If the egg does become fertilized it will attach itself to the uterine wall and a fetus will begin to develop.
This phase usually occurs about 14 days before the next period starts.
The final phase is the premenstrual phase.
If the egg does not get fertilized, then the thickened lining of the uterus is shed and a new cycle begins.
Periods will vary from month to month for the first few years.
Every woman is different therefore her body reacts differently.
The flow can be light, medium or heavy.
Although the norm is 3 to 5 days but 2 to 7 is still considered normal.
As a woman gets older her period should become regular enough that she can write it down on the calendar.
At around age 50 women stop having their periods when they reach menopause.
At this stage in life woman are no longer ovulating or making eggs.
Because of this she can no longer become pregnant.
Just like menstruation, menopause varies from woman to woman.
Many women don't experience menopause until their sixties.