While menstrual cycle length and symptoms can look different for everyone, what happens in your body during a healthy menstrual cycle should be consistent. Here’s why it’s important to track your menstrual cycle length and what irregularities to look out for.
The menstrual cycle is a series of changes that occur in your body as it prepares for the possibility of pregnancy each month. This cycle starts on the first day of your period and ends the day before your next period begins.
Average menstrual bleeding can happen anywhere in a “normal” menstrual cycle length, which is typically 21 to 35 days. However, menstrual cycles are difficult to predict as they can vary from cycle to cycle and are different for everyone. You may experience light or heavy flow, long or short periods, painful symptoms or no symptoms at all, and that might be the cycle that's “normal” for you.
The “normal” menstrual cycle length, along with its symptoms, varies for everyone and will change throughout your life until you reach menopause (when you stop ovulating). It’s important to understand your individual cycle to monitor and maintain your health and well-being.
Understanding a “normal” menstrual cycle length To understand a “normal” menstrual cycle length, it’s important to understand the different parts of your cycle and how long they may last.
There are four phases of the menstrual cycle–menstruation, follicular, ovulation, and luteal.
Menstruation: The menstrual cycle begins on the first day of your period when your uterine lining sheds out through your vagina if pregnancy hasn’t occurred. Average menstrual bleeding can happen every 21 to 35 days and can last on average from two to seven days .Follicular phase : This is the first phase of the menstrual cycle that starts when your period begins and ends at ovulation (it overlaps with the menstruation phase). Estrogen levels increase and the follicle-stimulating hormone prompts the follicles in your ovaries to grow to form a fully mature egg. This part of the cycle tends to last anywhere from 10 to 16 days .Ovulation : This phase occurs around day 14 of a 28-day menstrual cycle. Hormones cause the ovary to release an egg. Ovulation only lasts around 12-24 hours .Luteal phase : This is the second half of your cycle after ovulation. Progesterone levels increase to thicken the uterine lining and prepare for possible pregnancy. If the egg isn’t fertilized during ovulation, hormone levels drop, the thick uterine lining sheds, and you get your menstrual period. The luteal phase tends to last between 10-16 days .Overall, a normal menstrual cycle length is typically around 28 days, but anywhere from 21 to 35 days is still considered “normal.”
Yet the length of menstrual cycles can range for everyone. Longer cycles are typical in the first few years after menstruation begins, and then might shorten and become more consistent as people age. Your menstrual cycle might be the same length every month or more irregular.
Furthermore, certain kinds of birth control such as birth control pills or intrauterine devices (IUD) can regulate a menstrual cycle to be more consistent and ease your symptoms or to not occur at all.
By tracking your menstrual cycle , you can find what’s “normal” for you. If you notice any major anomalies in your menstrual cycle, it’s important to consult a healthcare professional.
Factors that affect a normal menstrual cycle length If your menstrual cycle length is outside of what’s considered a “normal” menstrual cycle length, what are potential underlying factors?
Hormones Hormones play a crucial role in directing each phase of the menstrual cycle. The rise and fall of certain hormones cause the uterine lining to thicken and the ovaries to release an egg during ovulation. Therefore, hormonal imbalances can affect the length and regularity of your menstrual cycle.
Hormone imbalances can stem from pregnancy and breastfeeding to more serious health issues such as eating disorders and dramatic weight loss, polycystic ovary syndrome (PCOS) , premature ovarian failure, pelvic inflammatory disease, and uterine fibroids.
Typically, the average menstrual cycle is around 28 days, with a luteal phase (the time between ovulation and the start of menstruation) lasting between 12 to 14 days . However, hormone imbalances can cause this phase to shorten or extend, both of which affect the menstrual cycle:
Short luteal phase : A short luteal phase lasts less than 10 days, so you get your period within 10 days of ovulation. Ten days is too short to let your uterine lining grow enough to support an embryo. This may be a sign of luteal phase defect —when your uterine lining doesn’t thicken enough to support a pregnancy. People with a short luteal phase may have more problems trying to conceive. Long luteal phase: Long luteal phases come 18 days or later after ovulation. People with a long luteal phase may have PCOS or other hormone imbalance issues. If you don’t get your period within 14 days of ovulation, it can also be a sign of early pregnancy. Take a pregnancy test to confirm. Age Menstrual cycles will also change as you age. During perimenopause , when your body is transitioning to menopause, you begin to experience periods that are less frequent or regular.
>>MORE: Perimenopause vs. Menopause: What’s the Difference?
Other Factors Additional influences, such as high stress levels, overexercising, or rapid weight changes, can also disrupt cycle regularity. Stress-related changes, in particular, affect hormone levels, potentially causing fluctuations in cycle length and frequency.
How to find your menstrual cycle length As menstrual cycles are unique to you, it can be helpful to track your menstrual cycle to identify any irregularities and monitor your hormonal health. Tracking your menstrual cycle is also useful if you’re trying to get pregnant so that you can determine when you’re ovulating and most fertile.
To find your menstrual cycle length, use a calendar and mark the first day of your period. Mark each day you’re bleeding and stop once you’re no longer bleeding. When the bleeding starts again, mark the calendar again. As you continue to do this over months, you can count the number of days between your periods to calculate the length of your cycle and how long your menstrual bleeding lasts.
There are also mobile apps, fertility trackers, and hormone tests like Oova that are also helpful methods for monitoring and understanding your menstrual cycle.
Oova’s at-home hormone tests are a convenient and effective way to track your specific hormone levels and understand your unique menstrual cycle and its phases from the comfort of your home. Oova can be used to track and predict ovulation whether you are trying to conceive, navigating perimenopause, experiencing a reproductive health condition like PCOS, and more.
Irregular menstrual cycle length Irregular menstruation is anything that’s not a normal menstrual period. This can include several signs and symptoms that may suggest underlying health concerns or changes in hormone balance.
Two main irregularities in menstrual cycle length include:
Periods stop for more than 90 days: Missing your period for over 90 days without a known cause, such as pregnancy or menopause, could indicate hormonal imbalances, stress, weight changes, or underlying health conditions that require attention.Cycles shorter than 21 days or longer than 35 days: A cycle shorter than 21 days or longer than 35 days is outside the standard range and may indicate hormone-related conditions, such as PCOS or thyroid issues, affecting cycle regularity.There are also non-time-based symptoms of irregular menstrual cycles, including:
Bleeding or spotting in between periods Bleeding that's much heavier or lighter than usual You develop severe pain during your period Suddenly you get a fever or feel sick after using tampons >>MORE: All About Irregular Cycles
If you experience these signs of irregular menstruation, it’s important to seek out a healthcare professional for help. Early intervention can often address underlying issues before they become more serious, helping to restore cycle regularity and overall health.
Normal menstrual cycle length: the bottom line As periods are different for everyone, so is the definition of what a “normal” menstrual cycle looks like. A “normal” menstrual cycle length is anywhere between 21 to 35 days. Your length may change from one cycle to the next, and may naturally change over time as you age and reach perimenopause.
By tracking your cycle, you’ll be able to identify any irregularities and if you notice any extreme changes, it’s important to consult your doctor. Menstrual cycles are key not only for reproductive health, but for overall well-being—your hormone balance is essential for bone, thyroid, and metabolic health. By monitoring your cycle length and symptoms, you can better understand what’s normal for you and take action.
