All about ovulation

All about ovulation

Detecting ovulation allows you to find out the following:

  1. If intercourse was well-timed around your fertile window for a conception to occur.
  2. If you can stop having ‘baby-making’ intercourse which may be more intentional, planned and frequent.
  3. The length of your luteal phase. That is the 2nd half of your cycle after you ovulate. The length of this phase needs to be long enough for a fertilised egg to have enough time to properly implant. If your luteal phase is too short, then you will get a period before implantation can occur.
  4. When to expect your period or a positive pregnancy test result.

What is ovulation

Ovulation is the release of a mature egg or ovum from the ovarian follicle. Each menstrual cycle, several ovarian follicles begin to mature and develop under the influence of pituitary hormones. Usually only one follicle develops fully. While the other follicles recede, this dominant follicle produces an egg which is released at ovulation ready to be fertilized. This growing follicle secretes increasing amounts of the hormone oestrogen. Following peak estrogen production, there is a surge of luteinizing hormone (LH). The LH surge triggers the release of the mature egg from its follicle and this is ovulation!

After ovulation

Once you have ovulated your egg is picked up by one of your fallopian tubes and begins to travel towards your uterus via the fallopian tube.

The follicle that released your egg becomes known as the corpus luteum after ovulation and begins to secrete the heat inducing hormone progesterone which causes your basal body temperature to rise.

The lifespan of your egg after ovulation is only 12 to 24 hours (one day), maybe even less. Fertilization must take place within that 12 to 24-hour time frame. After this time frame, the egg begins to degenerate and is no longer capable of being fertilized. This seems like a short window of time for conception to take place but remember that sperm can lie waiting in your body for up to 5 days prior to ovulation. So, the days before ovulation occurs are considered fertile days if you time intercourse around that time so that you have sperm waiting in your reproduction track ready for ovulation to occur.

Ovulation and the cycle phases

Ovulation is the event that defines the phases of the menstrual cycle. The phase before ovulation, when the ovarian follicles are developing is called the follicular phase. The phase after ovulation is called the luteal phase.

The length of the follicular phase may vary, but the luteal phase length is generally constant from cycle to cycle for the same woman, lasting 10 to 16 days. When cycles are irregular, it is usually because ovulation occurred earlier or later than usual. Knowing when ovulation occurred allows you to see if intercourse was well-timed in the fertile window for conception and helps you determine your luteal phase length. Knowing your luteal phase length tells you when to expect your period or a positive pregnancy test result.

When does ovulation occur?

Ovulation takes place about two weeks before your period, though it can vary from 10 to 16 days before the onset of menstruation depending on the length of your luteal phase. During a ‘textbook’ 28-day cycle, ovulation is usually expected to take place between cycle days 13 to 15. Based on this guideline, many women expect ovulation to occur around day 14 of their menstrual cycle. Many women, however, do not have average cycles and even those who usually do have regular cycle can see irregularities from time to time, so do not assume you will ovulate on or around day 14.

Detecting ovulation

Your ovulation date and your fertile window can be detected by charting your fertility signs. Your body produce signals that tells you that ovulation is approaching and when ovulation has passed. 

Fertility signs that indicate that oestrogen levels are high and ovulation is approaching and that you are fertile include observing increasingly stretchy and "egg white" cervical fluid and observing a high, soft and open cervix.

Commercial devices such as ovulation prediction kits (OPKs) and fertility monitors can also tell you that ovulation is approaching by measuring the presence of oestrogen or luteinizing hormone (LH) in urine.

Charting your basal body temperature (BBT) allows you to pinpoint the day of ovulation and tells you when ovulation has passed because progesterone raises the basal body temperature after ovulation.