It’s Totally Ok If Your Menstrual Cycle is More Than 28 Days

We are often told that a menstrual cycle is 28 days on average. However, a study published in the npj Digital Medicine journal based out the United Kingdom and Sweden says otherwise. The study analyzed 612,613 ovulatory cycles, taking into consideration data from the menstrual tracking app Natural Cycles including the users’ body mass index (BMI), basal body temperature (BBT) and luteinising hormone (LH) (Hensley). It was found that the average cycle for a menstruator is 29.3 days long and that only 13% of menstruators cycle’s were 28 days (Hensley).

In fact, variation in cycle lengths is perfectly normal, Dr. Yolanda Kirkham, an OB-GYN at St. Joseph’s Health Centre Toronto and Women’s College Hospital states that, “Twenty-eight is an average, but [cycles] can range anywhere from 21 to 35 days” (Hensley). The follicular phase (the phase that results in ovulation) can last anywhere between 12 to 19 days (Hensley). Menstrual cycles can vary from month to month, which means it’s normal if one month your cycle is 28 and the next it’s 29 or 30. Every menstruator is a little bit different so it’s ok if your menstrual cycle isn't completely consistent.

Furthermore, for young menstruators it’s completely ok to have skipped cycles one month and bleed a lot the next! When you’re young your ovulation is not yet in order and your cycle may take a few years to reach a regular recurring pattern.

So, if you’re worried why sometimes your cycles are longer or shorter than others, you can rest assured that it’s just your body doing it’s thing.

References

Hensley, Laura. “Most Menstrual Cycles Aren't 28 Days - and That's Normal - National.” Global News, Global News, 10 Nov. 2019, globalnews.ca/news/6134272/menstrual-cycles-28-days-average/.

Bull, Jonathan R., et al. “Real-World Menstrual Cycle Characteristics of More than 600,000 Menstrual Cycles.” Npj Digital Medicine, vol. 2, no. 1, 2019, doi:10.1038/s41746-019-0152-7.