A menstrual cycle is counted from the first day of the menstrual bleeding or period to the first day of the next period. The average menstrual cycle is 28 days long, while menstrual bleeding usually lasts 3-5 days. Cycles can range anywhere from 21 to 35 days in adults and from 21 to 45 days in young teens.
What are the phases of the menstrual cycle?
The menstrual cycle is typically separated into three phases:
- Follicular phase
- Ovulatory phase
- Luteal or corpus luteum phase
Between the ages of 12 and 52, a woman will have around 480 periods, or fewer if she has any pregnancies.
What if my periods are more frequent than every 21 days?
There are many circumstances where your period may come more frequently than every 21 days.
People in perimenopause, may experience shorter, more irregular cycles until they reach menopause.
Other factors that may shorten cycle length include:
- Stress
- Temporary illness, such as the flu
- Significant weight changes
- Hormonal birth control
- Uterine fibroids
- Kack of ovulation (anovulation)
Most commonly, your cycle duration will normalize on its own.
What if my periods are regularly delayed or late?
Occasional lateness may also be caused by:
- Stress
- Intense exercise
- Significant weight changes
- Hormonal birth control
- Perimenopause
Other health conditions may also affect the latency.