Ovulation Explained, Step by Step
What actually happens across a cycle, from the first hormonal signal to the moment an egg reaches the fallopian tube. Written by Claudia Ferreira for anyone trying to understand their own cycle.
In this article
Most of us were taught that ovulation happens on day 14 and left it there. What actually happens is a sequence of signals passing between the brain and the ovaries, and knowing the steps makes your own cycle far easier to read.
Here is the process, start to finish.
The sequence
1. The pituitary gland in the brain releases a hormone that signals the ovaries to produce fluid-filled cysts called follicles. These follicles grow and secrete oestrogen, which thickens the uterine wall in preparation for pregnancy.
2. Around day seven of the menstrual cycle, all follicles except one stop growing. This remaining follicle continues to grow and nourishes a maturing egg within it, known as an oocyte.
3. On day 12, the maturing follicle releases a burst of oestrogen into the bloodstream. This oestrogen travels through the blood and reaches the pituitary gland in the brain. In response, the pituitary gland releases luteinising hormone, which causes the follicle to experience a sudden growth spurt.
4. Just before ovulation, the mature egg detaches itself from the follicle. The follicle then releases chemicals that prompt the nearby fallopian tube to move closer and surround the follicle.
5. The follicle swells until it bursts open, expelling the egg and fluid into the abdominal cavity.
6. The fimbriae, small finger-like protrusions at the end of the fallopian tube, sweep across the burst follicle and pick up the egg.
7. The egg is transported to the entrance of the fallopian tube. Inside the fallopian tube, muscle contractions gently push the egg towards the uterus.
8. In the fallopian tube, the egg may encounter sperm and fertilisation can occur. Alternatively, if the egg remains unfertilised, it will continue its journey to the uterus and eventually be absorbed by the body.
Why it is worth understanding
Understanding the process of ovulation gives you useful insight if you are trying to conceive. Knowing the steps helps you read your own signals and make informed decisions.
A practical note on the day numbers above: they describe a textbook 28-day cycle. Real cycles vary, and yours may run longer, shorter, or less predictably. That is common and not automatically a problem. It does mean that tracking your own pattern over a few months tells you far more than any general timetable.
If your cycles are irregular, very painful, or absent, that is worth raising with your GP rather than working around. NICE guidance suggests seeking investigation after twelve months of trying to conceive, or sooner if you are 36 or over.
At the Marylebone clinic, cycle tracking is where fertility work begins. It shapes when sessions are timed within fertility acupuncture, and it is the first thing mapped in the 12 Weeks Fertility Reset Protocol.
Frequently asked questions
When in the cycle does ovulation happen?
In a textbook 28-day cycle the LH surge lands around day 12 and release follows shortly after, but real cycles vary widely and yours may be quite different. Cycle length, stress, illness and travel all shift the timing, which is why tracking your own pattern is more useful than assuming day 14.
How do I know if I am ovulating?
Common signals include a change in cervical mucus, a small rise in basal body temperature after release, and a positive result on an ovulation predictor kit detecting the LH surge. None is perfect on its own. If your cycles are irregular or absent, that is worth raising with your GP.
How long does the egg survive after ovulation?
An egg is generally considered viable for around 12 to 24 hours after release, while sperm can survive several days in the reproductive tract. This is why the fertile window is usually described as the days leading up to ovulation rather than the day itself.
Can acupuncture make me ovulate?
No, and we would not claim that. Acupuncture is offered here as supportive care alongside your medical treatment, not as a fertility treatment in its own right. If you are not ovulating, that needs medical investigation with your GP or a fertility clinic.