Why Did My Menstrual Cycle Change from 28 to 31 Days?

Understanding Menstrual Cycle Length Variations

“Why did my menstrual cycle change from 28 to 31 days?” While the human body tries to be consistent, there are natural variations that happen between us, which can be affected by internal or external influences. This also applies to the menstrual cycle. On average, periods can last 28 days, but there are often variations between individual people and even from month to month.

What Is a Typical Menstrual Cycle?

The menstrual cycle starts on the first day of your period, which kickstarts the follicular phase, where you may bleed for five to seven days (individual cycle dependent). You then have a few days of rest in the follicular phase before you enter the fertile window and after ovulation- beginning the luteal phase of the menstrual cycle. Ovulation happens in one day, but the fertile window is about five days. After that, you will be in your luteal phase for the rest of the cycle, and the inner lining of your uterus will start to thicken until you hit day one again and start your period. Generally, your heaviest flow of your period will be within the first two days and in total you could lose between 1 and 5 tablespoons of blood.

Why Cycle Length Can Vary

The most obvious reason is your age, however some health conditions like polycystic ovary syndrome (PCOS) and pelvic inflammatory disease (PID) may affect your cycle length. Lifestyle factors, such as stress levels, extreme weight loss, and some medications, also have a big effect on our cycle.

Is a Shift from 28 to 31 Days Considered Normal?

If this happens to you, you might wonder “Why did my menstrual cycle change from 28 to 31 days?” A shift in cycle length can be completely normal. It can be a natural shift in your hormones, emotional or lifestyle changes, medications, or health conditions. If you go for more than six weeks or 42 days without a period consider consulting your healthcare professional, as this is the maximum delay in periods if not pregnant.

Hormonal Fluctuations and Menstrual Cycle Changes

Your menstrual cycle is governed by your hormones, sometimes, this is perfectly natural, and sometimes we need to take note of it and check in with our physicians.

The Role of Estrogen and Progesterone

Estrogen plays a lot of roles, including thickening the uterine lining, being the catalyst of ovulation, and when estrogen levels drop, it kickstarts menstruation. Progesterone also thickens the uterine lining, but can stay high if conception occurs or drop low to start your periods.

How Hormone Levels Impact Cycle Length

Our cycles are hormonal cycles, and each hormone affects the other. Some hormones stop or start others from being created, so if there is an imbalance this can affect the cycle length.

Age-Related Hormonal Changes

When we hit puberty and start our periods, they will be less regular until our body gets the cycle truly underway. Alternatively when we get to between the ages of 45 and 55, we enter menopause, which will cause irregular periods until they stop altogether. 

Benefits of Cycle Tracking

Tracking your cycle can help you with planning (like not packing those white jeans for that vacation if your period will hit in the middle of it!), helping identify patterns, and help you adjust your lifestyle to make yourself and your period more comfortable. Your doctor may also want you to track it if you are exploring health conditions. 

Tracking can be easy, if you have the right tools, such as a place to keep your records and a way to keep an eye on your hormones. That’s where the Mira Hormone Monitor comes into play. It can track a variety of hormones involved in the menstrual cycle in an easy-to-understand way. Combining these with the Mira Max Wands that can track Estrogen-Estradiol Metabolite (E3G), luteinizing hormone (LH), and pregnanediol glucuronide (PdG) means you can predict your ovulation and fertility window. Using the Mira app to combine all this information will give you digestible information and help you predict when your cycle will be. If you’re not sure where to start or how to go about tracking the Mira Hormone Health Clinic for Fertility is a great place to start with our empathetic fertility experts who can answer all your questions.

Diet, Stress and Lifestyle Factors

We all know we need to have a healthy diet, limit how much stress we’re under, and live a healthy lifestyle. If something disrupts your menstrual cycle, it can be a sign that something isn’t right with your body.

The Effect of Stress on Menstrual Cycles

Believe it or not, too much stress can cause irregular menstruation, even going so far as delaying periods or causing you to miss one altogether! This is because stress releases cortisol into our body. Cortisol effectively blocks the release of luteinizing hormone (LH), which doesn’t sound like a problem until you know that LH is integral to ovulation. Without ovulation, you won’t be able to menstruate as the rest of the cycle is disrupted. One excellent way we can reduce stress is by practicing mindfulness. Doing this consistently can be hard, but the Mira Meditation Playlist makes it easy. With six meditation exercises to explore you can find what works best for you to reduce your stress the natural way.

How Diet, Exercise, and Sleep Influence Cycle Length

Keeping ourselves healthy and happy is important and different for all of us, but the absolute basics of what we need for our body is our nutrition, the condition of our body, and the amount of sleep we get. If any of these are out of balance, it can affect our periods, making them irregular, but there are extreme cases where your period might stop entirely. This is because diet, exercise, and sleep all affect our hormones in some way, and when those are out of balance so is our cycle. If this happens to you, consult your physician to get to the route of the problem. If there is a problem and you are looking to rebalance your hormones, there are some extra steps you can take. Multivitamins such as the Mira Prenatal multi-vitamins can help your body recover and get the vitamins needed to boost your immune system, help you relax, and boost your fertility. The Mira Fertility Tea is a way to help your normal monthly cycle with natural ingredients in a form that is also a calming ritual, helping settle your system.

Managing Lifestyle Factors for Cycle Consistency

If you can manage your stress, find a nutritious diet that works for you, balance your exercise needs, and keep your sleep consistent, it is possible to keep your period cycles manageable and relatively consistent. While irregular menstruation can be concerning, sometimes it’s just a symptom your body needs a lifestyle adjustment.

Health Conditions Affecting Cycle Length

There are some conditions that can affect your menstrual cycle and your average cycle length.

Thyroid Disorders and Menstrual Changes

The thyroid isn’t something we often think about when it comes to periods, but like all glands it is responsible for various hormonal processes, including our metabolism. When our thyroid is out of balance, or we develop thyroid disease it can throw everything out of whack, including our cycle patterns and the normal menstrual cycle length. Signs of this can be irregular periods, heavy or light periods, or even missed periods.

Polycystic Ovary Syndrome (PCOS) and Cycle Variability

PCOS affects our hormones, causing irregular or absent periods and other frustrating symptoms such as infertility or weight gain. It is possible for this condition to be controlled with help from medical professionals or fertility experts.

Other Health Conditions Impacting Menstrual Cycles

According to the Cleveland Clinic, if the cycle is affected it can be manifesting as amenorrhea (not having a period for three months), oligomenorrhea (infrequent periods), or dysmenorrhea (painful periods beyond what is normal). Uterine fibroids, endometriosis, and diabetes will also affect it. If you are struggling with these conditions, the Mira Hormone Health Clinic for Fertility has experts that can help you rebalance your hormones even with these conditions.

Changes in Birth Control or Medication

Some of us need medication to keep our body from falling apart on us. These medications are quite literal lifesavers but some of them can affect our cycles.

How Birth Control Affects Menstrual Cycles

Some forms of birth control can cause irregular or absent menstrual cycles, namely the progestogen-only pill (pop!) or other progestogen-only methods. It is also possible for it to cause breakthrough bleeds (bleeding outside of your normal monthly cycle days), irregular bleeding, or spotting. Your cycle should return after four weeks of not using this form of contraception but if you have concerns, speak to your practitioner.

Common Medications That May Alter Cycle Length

Some common culprits for disrupted cycles can include antidepressants (some SSRI medications can delay periods or make you miss them), blood thinners (which may cause bleeding), heart medications (some can cause heavy menstrual bleeding), steroids, thyroid medications, and antipsychotics (these can cause infrequent or missed periods or may cause menstrual cycles to go on for longer). If you are prescribed any of these and you have concerns about your cycle or TTC, speak to the practitioner prescribing them.

Pregnancy and Perimenopause Considerations

The initial thought a lot of us will have when we miss a period is “Am I pregnant?”, although this may transition into “Is this perimenopause?” as we get older. 

Early Pregnancy Signs and Missed Periods

If you miss a period and have headaches, fatigue, nausea, mood swings, needing to urinate frequently, or tender breasts, it could be time to take a test to see if you are pregnant. Remember though that pregnancy is different for everyone and no pregnancy is quite the same, so if you think you’re pregnant, take a test or talk to your physician. Sometimes we think we’re pregnant, but the test says we aren’t. If this is the case, then take a pregnancy test in a couple of days.

Perimenopause and Cycle Irregularity

Perimenopause is the transition to menopause. According to the NHS, this change can come with a variety of physical and mental health symptoms and can feel like a challenging transition. If you feel this is the case then there is help out there from your practitioner. If you are confirmed to be in perimenopause then the Mira Menopause Transitions Kit and the Menopause Transitions Mode in the Mira app can be useful tools to help you understand the changes in your body and give you confidence to enter this new life stage.

Knowing When to See a Doctor

Missing a single period or our cycle changing from its normal timings can make us question if we are ok or not. It’s totally normal to ask “Am I pregnant?”, “Is this perimenopause?” or “Why did my cycle change from 28 to 31 days?” but it’s good to know when we should be asking “Do I need to go to the doctor?”.

Red Flags for Menstrual Irregularities

Big red flags for cycle irregularities include missing three or more periods in a row, having cycles that are shorter than 21 days, bleeding outside of when you’re having your period or after sex, heavy bleeding (you can tell if you need a pad AND a tampon or if you’re changing your pad/tampon every hour or two), or periods that last for more than a week at a time. It is also worth telling your doctor if you experience these as well as weight loss, weight gain, excessive fatigue, dry or oily skin, and hair growth on your face.

Frequently Asked Questions