The 28-Day Cycle
A menstrual cycle is measured from the first day of your period to the first day of your next period. The average length of a menstrual cycle is 28 days, but everyone’s cycle is different. The four phases of the menstrual cycle are menstruation, the follicular phase, ovulation, and the luteal phase.
1. Menstruation
Otherwise known as your period. The average length of a period is three to seven days. Read more about menstruation here.
2. The Follicular Phase
The follicular phase starts on the first day of your period and lasts for 13 to 14 days, ending in ovulation. The pituitary gland in the brain releases a hormone to stimulate the production of follicles on the surface of an ovary. Usually, only one follicle will mature into an egg. This can happen from day 10 of your cycle. During this phase, your uterus lining also thickens in preparation for pregnancy.
3. Ovulation
Ovulation is when a mature egg is released from an ovary and moves along a fallopian tube towards your uterus. This usually happens once each month, about two weeks before your next period. Ovulation can last from 16 to 32 hours.
You may notice an increase in vaginal discharge at ovulation. This discharge is your cervical mucus and it is often copious and clear with an egg white type consistency. This type of mucus is “fertile mucus” and designed to help sperm to travel up the vagina, through the cervix and into the uterus to meet an egg.
It is possible to get pregnant in the five days before ovulation and on the day of ovulation, but it’s more likely in the three days leading up to and including ovulation. Once the egg is released, it will survive up to 24 hours. If sperm reaches the egg during this time, you may get pregnant.
4. The Luteal Phase
After ovulation, cells in the ovary (the corpus luteum), release progesterone and a small amount of oestrogen. This causes the lining of the uterus to thicken in preparation for pregnancy.
If a fertilised egg implants in the lining of the uterus, the corpus luteum continues to produce progesterone, which maintains the thickened lining of the uterus.
If pregnancy does not occur, the corpus luteum dies, progesterone levels drop, the uterus lining sheds and your period begins again.
What else happens to my body during these stages?
Follicular phase: You might notice higher energy levels, glowing skin and your sex drive may start rising. It’s common to feel optimistic and energised.
Luteal phase: without fertilisation of your egg, the change in level of progesterone can cause symptoms of PMS (pre-menstrual syndrome). You might notice mood swings, irritability, anxiety, bloating, fatigue, tender breasts, headaches, breakouts, or changes in appetite and sex drive.
Check out this fun video that visually explains how you might feel throughout your 28 day cycle
Iron
The levels of iron in your blood fluctuate throughout your menstrual cycle. This study found that your iron levels are at their highest during your luteal phase, and lowest during menstruation. Menstrual blood loss is a key contributor to the prevalence of iron deficiency, so it is important to replenish your iron through your diet or supplements.
Hormone levels
Because there are many different hormones that play a role in regulating your menstrual cycle, it is useful (and often beneficial for your health) to have regular blood tests to check and understand your hormone balance, even if you feel like everything is normal. If something isn’t right, these tests can check for hormone imbalance and flag and issues that you and your health provider can address to improve your health. Consult your GP or health provider to ask about getting a blood test.