How can I calculate my ovulation with irregular periods?

October 27, 2022
1:48 pm

Irregularities in your menstrual cycle may alarm you. Having irregularities is completely normal when your period first begins (menarche), and towards the end (perimenopause).¹ It is also normal to experience irregularities in your menstrual cycle after pregnancy, and if you are on and off contraceptives. However, having irregular periods can make it difficult to identify when your body is fertile enough for conception.

How to identify the “fertile window”

Period regularity can be characterised by the cycle’s length and how much it varies from one cycle to the next. An irregular cycle occurs when your menstrual cycle continuously falls outside of “regular” lengths. Another element that is typically taken into consideration is volume of menstrual bleeding and pain intensity.^[1]

That said, the fertility window starts approximately 3-5 days before ovulation and ends 1-2 days after ovulation.^[2] It is ideal for those who are actively trying to conceive to not only identify their ovulation period, but also their “fertile window”.

Calculating ovulation with irregular periods

With today’s modern technology and medical science, we have many options to identify and track fertile windows, even for women who experience irregular periods. Read on to learn about a few of the most common methods.

Calendar Methods

In order to make use of this method, start by counting your days in a cycle, beginning with the first day of your menstruation. Between days 12 and 19, you are considered fertile. Take note that this method may be hindered by some factors that affect the length and regularity of the menstrual cycle, such as contraceptives, menarche or menopause, or underlying health issues.^[3] Menstrual apps or period trackers can offer a convenient way to track your fertile window, but may not be the most accurate source to rely on, especially for women who face irregular menstrual cycles.

Home Ovulation Prediction Kits

Using home ovulation prediction kits are a convenient way to reduce the guesswork for figuring out when you are ovulating. These kits work by testing for the luteinizing hormone, a substance that causes the ovaries to release an egg. For the best chance of conception, intercourse should take place a few days before and after a positive result.^[4]

Body Basal Temperature

Basal body temperature (BBT) is one of the best methods of tracking ovulation for women with irregular menstrual cycles, as it is the simplest and the least invasive method to detect ovulation. BBT is defined as the lowest natural, non-pathologic (when you’re not ill) body temperature recorded after a period of rest.^[5] By tracking your BBT using a thermometer consistently, you may be able to predict when you’ll ovulate. For more definitive results, you should measure your oral, vaginal, or rectal temperature every morning after waking up and before intercourse is performed. You are at your most fertile during the two to three days before your temperature rises. To measure the changes in temperature, all you need to do is track your BBT using a thermometer that displays the result with one decimal point (e.g. 37.1°C).⁶

Cervical Secretion Methods

Cervical secretion methods are also a highly accurate method to determine ovulation.^[6] The main component of this method is checking for the presence of cervical secretions, then defining the secretions by colour, texture, and stretch of the secretion. To get the best results, check both at midday and early evening. Fertile cervical secretions are naturally clear, wet, and slippery, while infertile secretions are dry, sticky, and cloudy. During menstruation, women are still considered fertile, as menses can mask signs of cervical secretion.⁶

Above are the different methods, but don’t forget to check out fertility apps especially if you are tech savvy and not the type to keep records using pen and paper. Downloading a fertility app onto your smartphone will make tracking your menstrual cycle and fertility a breeze. With a multitude of fertility tracker apps available online, you should consider some details in helping you choose the app that is best suited for you:

Customer ratings and reviews (pros and cons)
Budget – free or paid
Accessibility and ease of use
Tools and special features: symptom management, irregular periods, etc

When you are someone who is busy and always on the go, having a fertility app is a smart and efficient way of keeping your ovulation in check, helping you to predict when you are most fertile and likely to conceive.

While these insights cover some of the more common methods used to identify ovulation, it is crucial to understand and listen to your body before starting your pregnancy journey. Wondering if you are fertile? Take our fertility questionnaire.

References

^[1] Dasharathy, Sonya S et al., “Menstrual Bleeding Patterns Among Regularly Menstruating Women,” OUP Academic, 20 February 2012, https://academic.oup.com/aje/article/175/6/536/85022#637267.

^[2] Detection of ovulation, a review of currently available methods,” PubMed Central (PMC), accessed 20 April 2022, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5689497/.

^[3] Pallone, S. R., & Bergus, G. R. (2009). Fertility Awareness-Based Methods: Another Option for Family Planning. The Journal of the American Board of Family Medicine, 22(2), 147–157. https://doi.org/10.3122/jabfm.2009.02.080038

^[4] editor. (2022, June 17). How to Use Ovulation Kits & Fertility Monitors. American Pregnancy Association. https://americanpregnancy.org/getting-pregnant/infertility/ovulation-kits/

^[5] Steward, K., & Raja, A. (2022). Physiology, Ovulation And Basal Body Temperature. In StatPearls. StatPearls Publishing.

^[6] Latz, L. J., & Reiner, E. (1942). Further studies on the sterile and fertile periods in women. American Journal of Obstetrics and Gynecology, 43(1), 74–79. https://doi.org/10.1016/s0002-9378(42)91334-6

MY-NONF-00162 | 27 Oct 2022 | 31 Oct 2022