Menstruation is just one part of a woman’s menstrual cycle. The menstrual cycle is a series of hormonal and physical changes that prepare a woman’s body for pregnancy. If pregnancy doesn’t happen, the body resets itself to prepare for another attempt at becoming pregnant.

Too Early, Too Late or Just Right?

Timing is everything to parents. Did she get her period too early? It is a problem that she hasn’t gotten it yet?

What Is a “Normal” Cycle?

A menstrual cycle is measured from the beginning of one menstrual period to the beginning of the next. The average menstrual cycle is about 28 days, but it can range between 21 to 45 days and still be considered a normal cycle. Menstrual bleeding typically lasts 3 to 5 days, although a range of 2 to 7 days can be the norm for some women. During the first few years after the first period, your teen’s cycles may not be regular or predictable. These early cycles are frequently anovulatory, meaning no ovulation occurs during the cycle. It would be impossible to predict which cycles would have ovulation or not, so it doesn’t mean teen girls in these early years are not fertile.

4 Phases of the Menstrual Cycle

The uterine lining, the ovum (egg) and hormone levels are all changing and cycling throughout the entire monthly process. There are essentially four phases of the menstrual cycle: menstruation, the follicular phase, ovulation, and the luteal phase.

When to Worry

Menstrual irregularities sometimes indicate a medical condition. There are a few instances in which your daughter should seek a doctor’s opinion. According to the U.S. Department of Health and Human Services, your daughter should see a doctor if:

She has not gotten her period by the time she is 15 years old. She has not gotten her period within 3 years after breast development or if breasts haven’t developed by age 13. Her period suddenly stops for more than 3 months. Her period becomes irregular after they were regular and predictable. Her period occurs more often than 21 days or less often than 45 days. Her period lasts more than 7 days. She is bleeding more heavily than usual or using more than one pad or tampon every 1 to 2 hours. She is bleeding between periods. She experiences severe pain during periods. She suddenly gets a fever or feels sick after using a tampon.

If there is ever a concern about your daughter and her menstrual cycle, talk to a trusted healthcare professional. Sometimes there are underlying hormonal issues or other concerns that your health care provider can address.