Probably the most talked about event of puberty for a girl is her period. Getting your period is another way of talking about menstruation. Within about a year after beginning her growth spurt, most girls will have their first period. This marks the beginning of a girl's life as a young woman. In some cultures, this is celebrated publicly. Others choose to be more private about it. Some girls can't wait for their first period to come, while others may dread it or feel neutral about it. No matter how you feel, it's an important event in your life and part of the normal process of becoming an adult.

There really isn't any way you can tell the day or week you'll get your first period. There also isn't really any way you can make it come sooner or delay it from happening. But you can understand what is happening inside your body to know what is normal for you.

During each period, the inner lining of your uterus is shed through the vagina, the passage that connects your inner reproductive organs to your outer sex organs (genitals). This lining is mostly blood and other tissues that have been building up since your last period. The purpose of this blood is to provide nutrients for a fertilized egg if you were to become pregnant. Girls start having their periods early in their lives, but most don't decide to start a family till they've already been having their periods for many years. Most women stop having periods when they are between 45 and 55 years old. This is called menopause.

You may have heard some women talking about their monthly cycle. This cycle begins on the first day of one period and ends on first day of the next period. While women's periods do tend to come about once per month, there is a wide range in the length of menstrual cycle from woman to woman. Some women's periods come as often as every 21 days, some as far apart as every 35 days. The most common range is 25-30 days. Some women have regular cycles and their periods start exactly the same number of days apart each time. For other women, the length of their cycle varies from month to month.

There is also a great range in how much blood flow each woman loses during her period. You may have a heavy flow and need to change your pad or tampon frequently. Or you may have a light flow with barely any blood loss. Usually your flow will be heaviest at the beginning of your period. It may start out light, get heavier, and then get lighter again until it's over. It's also common to see some small clots or pieces of tissue in your menstrual blood. Most women's periods last from 3 to 7 days.

Another thing that can vary is the color of the blood on your tampon or pad. Sometimes the blood from your period can be a dark, rust-like color. Other times it can be a bright red color. The color may vary according to where you are in your period or the heaviness of your flow. Pay attention to the rhythm of your body, so you'll know what is normal for you in terms of flow, cycle and period length, and color of your blood.