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What Causes a Missed Period?

What Causes a Missed Period?

There are many causes of a missed a period- WUKA experts discuss what it means when you skip a period, and what you can do to regulate your cycle.  

The average menstrual cycle 

The average menstrual cycle lasts for around 28 days, but in reality this can be anywhere from 21 to 35 days. If you track your cycle you’ll have a good idea of what’s normal for you. Regardless of length, every cycle will follow the same pattern each time, going through four separate stages.

  • Stage one: menstruation. Day one of your cycle begins on the first day of your period, when you bleed from your vagina. This usually lasts for around 2-5 days, but for some it can be up to 7 days. The bleeding is usually heavier to begin with, tapering off towards the end. Some people experience cramps and other PMS symptoms at this time too.
  • Stage two: follicular phase. The follicular phase actually starts at the same time as your period starts, as the body begins to already prepare for the next cycle. During this phase, hormones shift and follicles begin to grow on the ovaries, which stimulate oestrogen production. This triggers the growth and development of eggs, one of which will grow to full maturity.
  • Stage three: ovulation.  The ovulatory phase is the shortest phase of the cycle, and this is when the mature egg is released from the ovaries. It travels down the fallopian tubes, and if it meets a sperm it will be fertilised. If no pregnancy occurs, it’s reabsorbed into the body instead. 
  • Stage four: luteal phase. The luteal phase takes place as soon as ovulation has finished. During this phase, oestrogen levels fall sharply as progesterone rises, and this is where lots of people experience PMS symptoms such as low mood, anxiety, bloating, acne and sore breasts. As the hormones fluctuate, changes in the uterus begin to take place - the thickened lining begins to break down, and at the end of this phase it will be shed (along with the unfertilised egg) as your next period. This phase ends when your period begins.

What causes a missed period?

There are many potential causes of a missed period, so first and foremost it’s important not to panic. A missed period does not automatically mean you’re pregnant- although it’s always a good idea to take a test to rule that out if you think it could be a possibility. 

Other causes of a missed period include:


Stress can play havoc with your health and wellbeing, and is a major cause of a missed or delayed period. When we’re stressed, cortisol levels rise and this can suppress oestrogen, so taking steps to eliminate stress as much as you can is a really good idea.

Try to find activities that help you relax- exercise, such as yoga, swimming or long walks; mindful activities such as knitting, meditation, reading or gardening. Whatever it takes to lower your stress levels, give it a go. Try our period leggings for 100% protection during your next mid-cycle workout.

WUKA period leggings for an active lifestyle

If you’re chronically stressed, it could take some time to balance your hormones, so make it a priority to tackle the root causes of your stress, and remember that things such as over exercise, lack of sleep and a busy schedule can make stress worse too. 

Weight loss/ gain

Losing or gaining a lot of weight quickly can have an affect on your cycle too, as sometimes this can delay or stop ovulation- and if ovulation doesn’t occur, you won’t get a period. Likewise, your period could become irregular as hormone balances are disrupted and you could find your period difficult to predict. Speak to your GP about safe ways to lose weight if you need to, or ways that you can gain weight slowly and safely in order to regulate your cycle. Our Stretch Seamless period pants  are perfect for your changing body shape; they fit up to 4 different sizes, and provide support and comfort where you need it most, and all with a 100% leak-proof guarantee. Always there, always your size. 


Polycystic Ovarian Syndrome (PCOS) is a hormonal condition affecting up to 10 million women across the globe. People with PCOS have many partially formed follicles on the ovaries, which are unable or unlikely to grow into maturity, and therefore are unlikely to produce eggs for fertilisation. If no egg is produced, ovulation can’t take place- leading to a missed period. If you have PCOS, we recommend our Heavy Flow Period Pants, as many women find that when they do get their period it can be fairly heavy. Being protected and supported is one less thing to worry about. 

WUKA heavy flow period pants for irregular periods

Speak to your GP about managing your symptoms if you have PCOS.

Birth control

Some hormone birth control methods can disrupt your cycle when you first start to take them. This should settle down after a couple of months, but if it persists you should speak to your GP to find out why. Some women experience lighter periods or spotting between periods when they first start on hormonal birth control too; we recommend our light flow period pants to absorb these leaks, and keep another pair in your bag ready for your next period so you don't get caught off guard. 

Some contraceptive pills can be taken to intentionally delay your period too. It’s important to follow specific instructions when taking the medication- if you’re not sure speak to your GP for advice. 

Thyroid issues

According to the NHS, thyroid issues can cause irregular or missed periods, amongst other symptoms- including:

  • Feeling tired
  • Gaining weight
  • Being sensitive to the cold
  • Feeling depressed
  • Suffering with constipation
  • Feeling muscle aches and weakness
  • Loss of libido
WUKA Flex period pants

Speak to your GP if you suspect your may have a thyroid issue. And in the meantime, we recommend trying our WUKA Flex period pants to help you through your cycle. They're multi-sized so perfect for changing body shapes and period bloating, plus the Flex Bikini have detachable straps that enable you to remove and change them without undressing- a game changer when muscle aches and weakness make life hard. 


Perimenopause refers to the period of time before the menopause, where the ovaries stop producing oestrogen, ovulation ends, and periods stop. You’ve reached menopause when you haven’t had a period for over 12 months; for most this occurs around the age of 50-55. Before that, lots of changes can take place- including missed periods.

Perimenopause usually starts after the age of 45, and can last for up to ten years, so it’s important to know what the symptoms are and how best to manage them. One of the major signs of perimenopause is irregular periods, as the body starts to produce less oestrogen. This drop in oestrogen levels means that ovulation is skipped, and therefore you don’t get a period. This can happen for a couple of months in a row, before ovulation takes place again and you have another period.

WUKA Ultimate Super Heavy Flow period pants

Perimenopause can be unsettling, but it helps if you track your cycle so that you can get a better idea of what might be happening. And having the right pair of period pants can make all the difference too. When your flow is erratic, we recommend Super Heavy Flow pants, to catch all leaks and to give you gentle support if cramps are stopping you in your tracks. 


Premature Ovarian Insufficiency (POI) occurs when perimenopause begins before the age of 45. It affects 1 in 100 people under the age of 40 in the UK, and so far doctors aren’t sure what causes it. As with perimenopause, a major signal of the condition can be missed periods, as the body begins to produce less oestrogen. Again, periods can be erratic, and you might not know what your flow is about to throw at you- or when. We recommend keeping a pair of heavy flow period pants in your bag, just in case.  

If you think you may be experiencing POI symptoms, speak to your GP for advice.

Recently started your period

If you’ve only just started your period, you might experience irregular cycles for anywhere up to two years before things settle down into a more reliable pattern. This is totally normal. It can take a while for hormone levels to balance and for your period to become regular, so don’t stress. 

Try to track your cycle as much as you can, and take note of how you feel at certain points in your cycle. Knowing the signs that your period is on the way can be helpful in understanding your body and getting to know your cycle. Our new Teen Stretch Seamless period pants are perfect for younger girls and teens- available from age 8 to 16, each size stretches to accommodate growing bodies, meaning one pair truly will last- even while your body changes and develops through puberty. 


Breastfeeding can delay your period after birth, and for some this can be for up to six months or even longer. The reason why breastfeeding can cause a missed period is all down to hormones. The body produces prolactin in order to keep up with milk supply demands, and this hormone suppresses oestrogen, which then leads to a delay in ovulation and a missed period. 

postpartum period pants by WUKA

For most breastfeeding mums, as baby begins to drink less milk (around the age of 6 months), things start to even out again and periods return. However, you may find that some months you have a period, only to get nothing the next month. Your cycle could be unpredictable until your baby stops breastfeeding completely, so again its a good idea to track your cycle and symptoms so that you can have a better understanding of what’s happening.  

Our postpartum pants collection is perfect for this stage in your life- to absorb your lochia after birth, and to be on hand while your cycle regulates once more following pregnancy. 

Is it normal to miss a period?

If you’re experiencing any of the above, then yes- it’s normal for you to miss a period, And sometimes, we might skip a period for no obvious reason- this is called an anovulatory cycle. In simple terms, your body skips ovulation for some reason, and so you don’t have a period. There can be underlying reasons why this happens, so if you can rule out all of the above, speak to your GP about finding out why.

Sometimes a period isn’t missed, so much as late- and again, there can can also be many reasons why your period is delayed too. This can be down to similar reasons as above, and usually is nothing to worry about. Remember, we’re not machines- in fact, only 13% of us actually have a regular, 28 day cycle anyway!

How much of a delay is normal?

A delay of a few days is quite normal for most people, even if your period is usually very regular. However, if you experience much shorter or much longer cycles than normal (by around 7+ days either way) then it might be wroth speaking to your doctor to see if there’s a reason why it’s happening.

When to call the doctor

If you’re aged under 45, you’ve ruled out pregnancy and you’re experiencing missed periods for more than one cycle, then it’s a good idea to make an appointment with your doctor for further investigations. 

Amenorrhea is where a person misses several periods in a row, and again there can be many reasons why this is happening. Speak to your doctor about the potential reasons why your periods have stopped, so that you can go over treatments that are available to you. 

What does a missed period mean?

Related posts

Does Stress Affect Your Period?

What Causes Irregular Periods?

Period Problems

Bleeding Between Periods 

Causes of Late Periods

What is Amenorrhea?

Will my Birth Control Affect my Period?

Time Between Periods


Is it normal to miss a period and not be pregnant?

It’s very common to miss a period without being pregnant, but it should always be investigated as to why it’s happening. Usually, there is nothing to worry about and if you take steps to alleviate stress and to balance your hormones your cycle should return to normal quickly.  

If you’re over 45, there’s a good chance that perimenopause is causing your missed period, but its also worth knowing that this sometimes happens to younger women too. Speak to your GP if you’re concerned.

Is it possible to miss a period for a month?

There are many reasons why you could miss a whole period, and in most cases there is nothing to worry about. You know your body best, however- so if you’re concerned, make an appointment with your doctor to discuss what could be happening. 

How much delay in periods is normal?

A delay of up to 7 days is normal and usually nothing to worry about. If your period is delayed for longer than this, it could indicate an issue which might need to be investigated. Cycle tracking is the best way to know whether or not your period is truly delayed, and knowing the signs of ovulation and menstruation can be hugely beneficial too.