Ovulation is the release of a mature egg from an ovary into the fallopian tube, which is then ready and able to be fertilized within 12 to 24 hours [1]. Knowing when you are ovulating is essential when you are trying to conceive. Here are some helpful facts about ovulation and how to track it.
Your fertility window
Just because the egg is more likely to be fertilized within 12-24 hours does not mean that it is the only time where sex can result in pregnancy. Sperm “lives” longer than an egg, so intercourse three to five days before ovulation can still result in conception because viable sperm can still be within your reproductive tract. In contrast, intercourse that happens after ovulation is unlikely to result in conception.
Tracking your ovulation with tests and kits
Folliculometry (an ultrasound of the ovaries) can be performed several days in a row to determine when you ovulate; it is an involved and often expensive method that doctors tend to reserve for patients with fertility challenges or who are undergoing procedures such as IVF or artificial insemination. Women with relatively predictable menstrual cycles can use at-home ovulation kits, which test for the luteinizing hormone (LH) in urine or estrogen changes in saliva [1]. Keep in mind that a positive result doesn’t indicate that ovulation is happening at that precise moment, as it can come up to two days after LH peaks. Additionally, in 7 out of 100 cycles, ovulation tests show a false positive result [2].
Tracking your ovulation naturally
There are several ways to track ovulation. Combining the following methods gives you the best chances of tracking it naturally.
Calendar method: This method is based on the assumption that ovulation occurs in the middle of your menstrual cycle (on the 14th day of a 28-day cycle). Conception is most likely during the five days before ovulation, plus an extra day after, while the egg is still viable in the fallopian tube. That means you can conceive from day nine to day fifteen of your cycle. This method does not translate well for women with cycles shorter than 25 days or longer than 32 days [2]. Cycle tracking apps have improved the calendar method by considering individual parameters and providing a more accurate prediction. However, ovulation does not always arrive on schedule. Apps tend to determine the day an egg is released with an accuracy of no more than 21% [2].
Basal body temperature monitoring: When you ovulate, your body temperature rises slightly. This method requires you to track and record your body temperature to detect the increase. You can do this by using an oral or rectal thermometer at the same time and under the same conditions every day. One thing to note is that when you notice an increase in your temperature, it may already be too late to conceive. Your best chance of conception will be two to three days before your temperature rises [3].
Cervical mucus: Three to four days before ovulation, the hormone estradiol softens the cervix and increases mucus secretion. This mucus is clear, wet, and similar to an egg white and it signals that you are within your fertile window [2]. The mucus will continue to appear throughout ovulation but will soon become thicker and cloudier, or virtually disappear. Tracking ovulation by checking your cervical mucus should be done with the same record-keeping discipline as the calendar and basal body temperature methods.
