How to Deal with Irregular Menstrual Cycles?

last updated on: 03.06.2025 | Medical review by:

Mayara Belli

Nutritionist

Much more common than people realize among women of reproductive age, irregular menstrual cycles can cause a lot of sleepless nights for many women. There could be several reasons for this—whether a woman wants to get pregnant, wants to avoid pregnancy, or simply doesn’t know exactly when her period will show up. The uncertainty of an irregular menstrual cycle can, in some cases, be very confusing, especially for women who are not using contraceptive medication. But why do irregular menstrual cycles happen and how can you deal with them if you’re trying to conceive? Does it affect your chances of getting pregnant? How can you work around this issue? Is there a way to tame a rebellious menstrual cycle?

First of all, we need to understand the menstrual cycle¹. The cycle itself always begins on the first day of true bleeding. You shouldn’t count days of spotting or light bleeding if they occur. Remember: the first menstrual day is when there is true (darker or clotted) blood and a real flow, even if it is light. From there, you can count approximately how many days your cycle is. To be sure that you have an irregular cycle, do the math for your last three cycles. If you don’t remember the exact day your period started, start counting from your next period, and you’ll find out how many days, on average, it takes for your period to return.

An irregular menstrual cycle is characterized by a lot of fluctuations—in other words, there’s a considerable difference in days from one cycle to another. Cycles with a variation of 2, 3, even up to 7 days are not considered severely irregular; it could simply indicate delayed ovulation or changes in the luteal phase (after ovulation). Irregular cycles can vary for shorter or longer—one cycle may be 21 days, another 35, then 28, then 70 days… The number of days can vary a lot! A cycle with a lot of variation can be a major headache, especially if you’re trying to conceive.

How to Deal With Irregular Menstrual Cycles?

To learn how to deal with an irregular menstrual cycle, you need to get to know your body. Fortunately, this isn’t too difficult. You just need to learn how to identify cervical mucus. The Billings method is very useful and should be used for this purpose². In fact, all women should learn the Billings method—it’s reliable and works for those who want to have a baby as well as those who do not. Keep in mind that the more elastic and transparent your mucus is, the closer you are to ovulation. Some women simply cannot determine their fertile window because they don’t know how many days their cycle will be. That’s why it’s important to learn how to detect ovulation regardless of how many days your cycle lasts. The wetter your vagina is, the more fertile you are, so you just need to have sex to increase your chances of conceiving—or avoid sex during this period if you don’t want to get pregnant.

Irregular menstrual cycles³ make it difficult for women who are trying to conceive because there’s no set time in the month for things to happen, as there is with women who have extremely regular cycles. It’s amazing to see that some people’s bodies operate almost on a schedule! The dream of anyone trying to conceive is to have a very regular cycle. But since that’s not your reality, it’s important to find ways to overcome this hurdle.

Dealing with irregular menstrual cycles is very personal; each woman learns to cope with it differently, but it’s very important to talk to your gynecologist so they can investigate what’s happening with your irregular menstrual cycle. Hormone tests are effective, and transvaginal ultrasounds can pinpoint the reason for an irregular cycle if there is a problem. However, if no problem is found, irregular cycles are simply a characteristic of your body.

To tame a menstrual cycle with these characteristics, you may need to use prescription medications from your doctor, or even natural options that can be very effective, such as vitex. It is worth having a conversation with your gynecologist to decide which option is best for you, whether you’re trying to get pregnant or just want to regulate your periods. It’s also worth mentioning that the menstrual period—the days a woman is on her period—can also change, so if you used to have your period for 3 days and now it lasts 5, or simply varies every cycle, that’s also considered normal!

Golden tip: Find the average of your cycle length to learn to identify your fertile days. For example, if you had a 21-day cycle, then a 35-day cycle, and then a 28-day cycle, your average would be 29 days, so you should have sex from the 12th to the 20th day of your cycle to cover the fertile window. Always on alternate days, okay? If you have any questions, use an ovulation calculator and good luck!

Photos: Alden Chadwick

References:

1Mihm, M., Gangooly, S., & Muttukrishna, S. (2011). The normal menstrual cycle in women. Animal reproduction science, 124(3-4), 229-236.
2Attar, E., Gokdemirel, S., Serdaroglu, H., & Coskun, A. (2002). Natural contraception using the Billings ovulation method. The European Journal of Contraception & Reproductive Health Care, 7(2), 96-99.
3Small, C. M., Manatunga, A. K., Klein, M., Dominguez, C. E., Feigelson, H. S., McChesney, R., & Marcus, M. (2010). Menstrual cycle variability and the likelihood of achieving pregnancy. Reviews on environmental health, 25(4), 369-378.

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