8 Period Myths and Misconceptions

8 min read
8 Period Myths and Misconceptions

Periods have been happening for as long as humans have existed, yet somehow they’ve accumulated an impressive amount of misinformation along the way.

Some period myths are harmless. Others can make people feel embarrassed about their bodies, use contraception less safely or put up with symptoms that deserve medical attention.

So here are eight common period myths we’d quite happily retire. 

Key takeaways

  • A healthy menstrual cycle doesn’t have to be exactly 28 days.
  • Some cramping is common, but period pain that disrupts your life deserves assessment.
  • PMS and PMDD are real cyclical conditions, not imagined symptoms.
  • You can exercise and swim during your period if you feel up to it.
  • There is no medical reason you can’t have consensual sex during menstruation.
  • Pregnancy can still occur from sex during a period in some circumstances.
  • Small period clots can be completely normal.
  • There isn’t convincing evidence that people who live together synchronise their menstrual cycles.

On this page

Myth 1: A normal menstrual cycle is 28 days

Twenty-eight days is often used as the textbook example of a menstrual cycle, but bodies haven’t read the textbook.

For adults, menstrual cycles commonly fall somewhere between about 21 and 35 days.

A typical period itself usually lasts around 3 to 7 days.

That means a 24-day cycle or a 33-day cycle can both fall within a typical range.

Your cycle can also vary slightly from month to month.

What matters more is your individual pattern and whether something changes significantly.

Very long cycles, very frequent periods, bleeding between periods or periods that disappear for months deserve a closer look.

Our guide to the menstrual cycle explains how the different phases fit together.

Myth 2: Bad period pain is just something you have to tolerate

Some cramping around the start of a period is common.

That doesn’t mean debilitating pain is something you should simply learn to live with.

Australian guidance considers period pain more concerning when it:

  • stops you doing normal activities
  • causes you to miss work, school or exercise
  • is getting progressively worse
  • occurs between periods
  • occurs during sex

Conditions such as endometriosis, adenomyosis and fibroids can all contribute to painful periods.

Heat, anti-inflammatory medicines where appropriate, hormonal treatment, TENS and other approaches can help depending on the cause.

Read our guide to period pain and what can actually help.

Myth 3: PMS is all in your head

No, it isn't. Premenstrual syndrome (PMS) describes recurring physical, emotional and behavioural symptoms that occur in relation to the menstrual cycle.

Symptoms can include:

  • bloating
  • breast tenderness
  • headaches
  • fatigue
  • irritability
  • anxiety
  • low mood
  • sleep or appetite changes

There is also a more severe condition called premenstrual dysphoric disorder (PMDD), which involves severe cyclical mood symptoms that can significantly affect daily functioning.

PMS and PMDD are linked to the body and brain’s response to hormonal changes across the menstrual cycle. They aren’t character flaws and they aren’t simply someone being “moody”.

Myth 4: You shouldn’t exercise or swim during your period

There is no medical reason most people need to stop exercising simply because they have their period.

In fact, gentle or regular exercise can help some people manage period pain and mood symptoms.

That might mean:

  • walking
  • running
  • strength training
  • swimming
  • cycling
  • yoga
  • whatever movement feels good for you

You also don’t have to force yourself through a hard workout because someone on social media says exercise will “fix” your period.

If you feel tired or sore, resting is allowed too.

Swimming during your period is also completely possible. Tampons, menstrual cups and menstrual discs can all be used while swimming when they suit your body and are used correctly.

See our guide to swimming on your period.

Myth 5: You shouldn’t have sex during your period

There is no medical rule saying consensual sexual activity has to stop when menstruation begins.

Whether you want period sex is entirely personal.

Some people enjoy it, some find increased lubrication useful, some find orgasm or intimacy helps them feel better and others simply don’t feel like being touched when they’re bleeding.

All of those are valid.

You can still transmit sexually transmitted infections during menstruation, so safer-sex practices remain important.

And despite another persistent myth, having your period isn’t reliable contraception.

For practical ways to reduce mess and choose suitable products, read our guide to period sex.

Myth 6: You can’t get pregnant during your period

The chance may be lower at some points during menstrual bleeding, but pregnancy is still possible.

The reason comes down to timing.

Sperm can survive in the reproductive tract for up to around 5 days.

If you have a shorter menstrual cycle or ovulate soon after your period, sperm from sex towards the end of your bleed may still be present when ovulation occurs.

Cycle timing can also change from one month to another, so estimating ovulation purely from calendar dates isn’t foolproof.

If avoiding pregnancy matters, don’t assume menstrual bleeding gives you a contraception-free window.

Read our guide to contraception options in Australia for more.

Myth 7: Period blood clots always mean something is wrong

Seeing a clot in your menstrual cup, disc, pad or toilet can look dramatic, but small clots can be a normal part of menstruation.

Clots are often more noticeable on heavier-flow days.

If you’ve switched to a cup or disc, you may notice them more simply because the menstrual fluid is collected rather than absorbed.

That doesn’t mean every clot should be ignored either.

Australian health guidance lists regularly passing clots larger than a 50-cent coin as one possible sign of heavy menstrual bleeding, particularly when it occurs alongside:

  • very heavy flow
  • frequent leaking
  • prolonged periods
  • significant pain
  • fatigue, dizziness or shortness of breath

Read our full guide to period blood clots and what’s normal.

Myth 8: Your period will sync with people you live with

This one is wonderfully persistent.

Roommates, partners, friends and family members often notice their periods overlapping and conclude that their cycles have synchronised.

It feels convincing because menstrual cycles naturally vary in length.

If two people menstruate regularly, their periods will sometimes move closer together, overlap and then move apart again simply by chance.

The original research suggesting menstrual synchrony became popular in the 1970s, but later research found important methodological problems and repeated studies have failed to show convincing evidence that people’s menstrual cycles biologically synchronise because they spend time together.

So if you and your best friend both start bleeding on Tuesday, enjoy the solidarity. Just don’t assume your ovaries are communicating.

A period can be normal without looking exactly like someone else’s

One of the problems with period myths is that they create a very narrow picture of what menstruation is supposed to look like.

Every cycle doesn’t need to last 28 days. Every period doesn’t feel the same. Some people exercise through theirs, others want a heat pack and the sofa.

The useful question isn’t whether your period matches somebody else’s idea of “normal”.

It’s whether you understand your usual pattern and can recognise when something changes or begins affecting your health or everyday life.

If you want to get to know your own pattern better, use Period Shop’s free downloadable period tracker.

Frequently asked questions

Does a period have to come every 28 days?

No. Adult menstrual cycles commonly range from around 21 to 35 days, and there can be some variation between cycles. Persistent changes or very irregular periods are worth discussing with your doctor.

Is severe period pain normal?

Mild cramping around the beginning of a period is common, but pain that regularly stops you working, studying, sleeping or doing normal activities deserves medical assessment.

Can you swim while you have your period?

Yes. You can swim during your period. Tampons, menstrual cups and menstrual discs are options for internal period protection while swimming.

Can you have sex during your period?

Yes, if everyone involved wants to. Menstruation itself isn’t a medical reason to avoid sex, although STI protection and contraception still matter.

Can you become pregnant during a period?

Yes, it is possible. Sperm may survive for up to around five days and someone with a shorter or unpredictable cycle may ovulate soon enough after bleeding for pregnancy to occur.

Are period clots normal?

Small occasional clots can be normal, especially on heavier-flow days. Regularly passing clots larger than a 50-cent coin alongside heavy bleeding or other symptoms is worth getting checked.

Do periods really sync?

There isn’t convincing evidence that menstrual cycles biologically synchronise between people who spend time together. Periods can overlap by chance because cycle lengths naturally vary.

Related reading

Sources and further reading

This article provides general educational information and isn’t a substitute for individual medical advice.