Each month, the body goes through a number of hormone-driven changes to prepare for a possible pregnancy. This series of events is known as the menstrual cycle.
The menstrual cycle in a nutshell
During each cycle, an egg is developed and released from the ovaries and the lining of the uterus builds up. If a pregnancy doesn’t happen, the lining sheds during the period and the cycle starts again.
This means that a cycle is counted from the first day of one period up to the first day of the next period.
Example:
Period 1: 15 – 21 July
Period 2: 14 – 19 August
Cycle length: 30 days
To calculate my cycle length, I count from 15 July to 13 August. My second period started on 14 August, so this is what I count as day one, which makes it a 30-day cycle.
What is a ‘normal’ cycle?
A period that happens every 21 to 35 days is considered a typical regular cycle, but everyone’s normal is different. It’s all about figuring out what your normal is!
Most periods last 3 – 5 days on average, but anywhere from 2 – 7 is usual.
Phases of the menstrual cycle
A menstrual cycle is more than just a period, it can actually be divided into four phases:
When should I see a doctor?
If you haven’t had your first period by the age of 16, it is recommended you see a doctor [1]. You should also see a doctor if your periods were once regular and have become irregular [2].
If you are bleeding heavily and longer for 7 days, this is not normal. Excruciating period pain is another thing you should always see a doctor about.
If you are bleeding outside of period, make a note of what cycle day it is and contact your doctor.
Further reading:
- What is an irregular cycle?
- 3 Ways To Make Periods More Inclusive
- Tips For Talking About Periods With Kids
References