The Fertility Cycle: Everything You Need to Know to Understand Your Body

What is the fertility cycle?

Fertility is controlled by hormonal changes that occur every month in a woman’s body. The cycle begins on the first day of your period and ends the day before your next period starts. Throughout this time, the body goes through several important changes to prepare for a potential pregnancy. The cycle is regulated by hormones such as FSH (follicle-stimulating hormone), LH (luteinising hormone), oestrogen, and progesterone. These hormones play a key role in ovulation and the uterus's ability to receive a fertilised egg.

The four phases of the fertility cycle:

1. Menstruation (days 1–5): This is when the uterine lining is shed, and you experience bleeding. Hormone levels are at their lowest.
2. Follicular phase (days 6–14): The ovaries begin producing follicles, one of which will become dominant. Meanwhile, the uterine lining thickens.
3. Ovulation (day 14): A mature egg is released from the ovary. This is the most fertile time of the cycle.
4. Luteal phase (days 15–28): Progesterone increases, preparing the uterus for implantation. If no fertilisation occurs, hormone levels drop and a new cycle begins.

How to track your fertility cycle

You can track your cycle using a calendar or a fertility app. Some also monitor basal body temperature each morning—after ovulation, your temperature slightly rises.

Tips to increase your chances of conceiving:

• Have sex around ovulation, when fertility is highest
• Use ovulation tests to identify peak days
• Sperm can survive up to 5 days, so timing is key