When it comes to female fertility, one of the main topics discussed is ovulation. For something that happens every month, ovulation remains a physical process few people fully understand (and that's where we come in!).
Here are some of the top questions fertility patients ask about ovulation and what you need to know.
To break it down further: your ovaries contain lots of fluid-filled follicles, and each follicle most likely contains an egg. During each menstrual cycle, one of these follicles responds to a shift in hormones to grow and mature. This follicle is deemed the Dominant Follicle.
Once the egg inside the dominant follicle is mature, the body releases a hormone called Luteinizing Hormone, which triggers the Ovulation process. Within 24-36 hours after this LH surge, the egg releases into the fallopian tube in order to be fertilized.
If the egg is fertilized, it travels down the tube and implants in the uterus. If the egg does not become fertilized, menstruation begins about 2 weeks after ovulation and the cycle begins again.
The length of the menstrual cycle (which is different for everyone!) determines when ovulation occurs.
The menstrual cycle is made up of 2 phases, separated by ovulation.
Phase One (Follicular Phase): In the first phase of the menstrual cycle, the body grows an egg to maturity. This stage varies in length from person to person.
Ovulation of the mature egg
Phase Two (Luteal Phase): The second phase is the opportunity for the egg to be fertilized. This phase typically lasts about 14 days from ovulation through the start of the next menstrual cycle.
If you know the length of your cycle each month, you can mathematically work backwards to estimate your ovulation day.
For example, if you have a 28-day cycle and calculate the second phase of your cycle as the typical 14 days, that means the first phase must also be 14 days (28-14=14). Knowing that, you can anticipate that you typically ovulate around day 14 of your cycle. Ovulation predictor kits are a great way to confirm that estimation.
How do I calculate the length of my cycle?
Your cycle length is calculated from the first day of one period to the first day of the next period. The first day is considered to be the first day of full flow (spotting doesn’t count).
Ovulation —the release of the egg from the ovary into the fallopian tube—occurs within a window of about 24 hours.
Luckily, there is a larger window of time to try to conceive due to the sperm’s ability to live within the reproductive tract for between 2 and 5 days. Of course, the closer you have intercourse to the time of ovulation, the better the chances are to conceive. Having regular intercourse as you near ovulation can help to ensure that some sperm are present at the time of ovulation.
If you have regular menstrual cycles lasting between 24-35 days, you are presumed to be ovulating at some point during the cycle. In order to confirm ovulation more exactly, however, you can test your hormone levels in one of two ways:
Use an at-home urine Ovulation Predictor Kit (OPK), which detects the presence of LH in your urine, or
Have your doctor draw blood to check for elevated LH at the time of ovulation and elevated progesterone following ovulation.
Ovulation predictor kits are a small paper test strip or digital test that is readily available at your local drugstore or through online retailers like Amazon. Depending on the brand that you use, the positive indicator can be anything from a simple line to a digital smiley face.
The best way to detect ovulation with an OPK is to use the kit each morning with the first urine of the day. Most kits require exposure to the urine sample and then have a few minute wait period before the results appear.
Read the packaging of your OPK to make sure you understand what indicates a positive result. Once a positive result is shown, you can anticipate ovulation happening within 24 to 36 hours. In order to conceive, it’s best to have intercourse the day of the positive OPK and the day after.
It’s best to start using the OPK about 4 or 5 days prior to when you anticipate ovulation to occur. That way you can make sure not to miss the positive if it happens earlier than expected. For example, in a 28 day cycle you would want to start using the OPK around cycle day 9 or 10 and continue each morning until you get a positive result.
If you never receive a positive result, there could be a few reasons why:
You may have missed the right time frame to detect ovulation
You may not have ovulated this month
Your LH level may be below the OPK’s threshold level
You had a faulty OPK or you are using it incorrectly
If you never receive a positive result, you should test again the following month and start using the OPKs a few days earlier than you did this month. If after three months of testing you repeatedly do not get a positive OPK, contact your doctor for further questions and testing.
It’s best to have intercourse the day of the positive OPK and the day after.
With successful Fertilization, you can expect to have a positive pregnancy test by the 14th day after ovulation (remember: the second phase of the menstrual cycle lasts about 14 days). This would be the same day that you would anticipate your period to start in the case where conception has not occurred.
Now that you know more about ovulation, you can put this knowledge into practice throughout your fertility journey. The more you know about your body, the better you can participate in your fertility care and advocate for yourself along the way!