Days of the week written down with bloody blobs partially covering them
Home/Cycle Matters / Period & Bleeding

How long do periods last?

Lauren headshot

Written by Lauren McKay

Lauren McKay

Lauren McKay is a writer and journalist with more than ten years of experience writing across a variety of topics. She is a passionate advocate for driving women’s health knowledge and is a trained yoga teacher. She earned a Masters in Creative Writing from the University of Glasgow and currently lives in Scotland.
Jack in a suit and tie holding a microphone and giving a presentation.

Fact checked by Jack Pearson, Medical Affairs Manager at Natural Cycles

Jack Pearson

Dr. Jack Pearson is a previously HCPC registered Embryologist with a PhD in reproductive medicine. Prior to joining Natural Cycles leading Medical Affairs, he worked for more than 10 years in a clinical setting working at some of the busiest fertility clinics in the UK. Today he spends most of his time working with experts at the world’s leading institutions to carry out important research with the vision to further the field of female health. He earned his PhD from the University of Sheffield specializing in Sperm Metabolism and currently lives in London.
Whether yours lasts for a couple of days or more than a week, your period length is unique to you, and depends on a number of factors. It’s completely normal, to wonder if yours is, well, normal! We’re here to bust some myths around periods, menstrual cycles and more so keep reading to learn ‘how long do periods last?’

What is a normal period length?

It all depends on your body and your menstrual cycle. This is counted from the first day of one period to the day before you get your next period. It’s not the same for everyone, meaning you might have a menstrual cycle of 20 days, while others could have one that lasts for 40 days. 

What’s more, you could have regular periods, meaning you get your menstrual period at the same time every month, and it lasts the same amount of time every month - or you could have irregular periods, with the length of your menstrual cycles varying from month to month, and your period length also varying. You may also have light periods, or heavy menstrual bleeding, or something in between. 

The range of what’s ‘normal’ when it comes to menstrual cycles and period length is very broad. A typical menstrual cycle is usually thought to be 28 days, but anything between 21 and 35 days is considered ‘normal’ - although our research into the menstrual cycle found that just one in eight women have a 28-day cycle. So, when it comes to ‘normal’, it’s really important to think about what’s normal for you. 

A ‘normal’ menstrual cycle follows these stages:

  • Days 1-5: The follicular phase starts on the first day of your period, and finishes when ovulation starts. During this phase, follicles containing an egg start to develop in the ovaries.
  • Days 6-8: Your estrogen levels start to rise, which causes your uterine lining to thicken.
  • Day 8: In a typical menstrual cycle, your period will stop after a maximum of 8 days.
  • Days 14-24: Ovulation usually happens on one day during this window. After ovulation, progesterone levels start to rise, and the lining of your uterus starts to thicken.
  • Days 25-30: In the last few days of your menstrual cycle, your progesterone and estrogen levels both start to drop, as the unfertilized egg leaves your body.

You’ll usually find that your period length is similar from month to month, and your menstrual cycle tends to be a similar length each month, too. While it may vary slightly each month - for example, one month your period lasts for four days, and the next month, it lasts for five - you should keep an eye out for any more significant changes to the length of your menstrual cycle or any irregular bleeding. 

A typical period length is two to seven days, but again, this varies from person to person and can be affected by a wide range of factors, from medical conditions like polycystic ovary syndrome to whether you’re using any hormonal birth control.

Period length in adolescence can be unpredictable for a while, but their menstrual cycles typically start to regulate by the time they’re in their late teens or early twenties.

Prolonged or irregular bleeding on birth control

If you use hormonal birth control, you may find that your periods are either longer or shorter than the ‘typical’ two to seven days. 

Hormonal birth control contains hormones including estrogen and progesterone, which work to thicken the mucus that lines the cervix, therefore preventing ovulation. 

Many people find that they have irregular bleeding when they start hormonal birth control, particularly in the first couple of months of taking a new type of contraception.

If you take birth control pills, then the bleeding you get when you take a break between pill packs isn’t a real period. It’s actually called ‘withdrawal bleeding’ and is simply a result of the levels of hormones in your body dropping. It’s usually slightly lighter than a natural period, if you run pill packets together you may skip bleeding altogether - this is perfectly healthy, and the idea that we need to cleanse the body or give the body a break between pills is a myth.

Other types of hormonal birth control such as the implant or IUD can also cause irregular bleeding. Many women taking these types of birth control will find that they have very light periods because the lining of your uterus doesn’t thicken as much as it would without hormonal birth control, which usually results in a lighter and shorter period. However, this isn’t true for everyone, and some people do experience long periods while using this type of contraception.

There are two types of intrauterine devices (IUDs): the hormonal IUD and the copper IUD. When using the hormonal IUD, as with other forms of hormonal birth control, many women experience lighter periods or may find that their periods suddenly stop.

The copper IUD, on the other hand, is a non-hormonal form of birth control, and most women find that they have prolonged bleeding with this method, especially in the first 6-12 months after having it inserted. You may also experience heavy periods, which are thought to be down to the changes to blood flow in your uterus.

Any menstrual irregularities you experience when taking birth control should settle down within the first couple of months, so it’s important to track what’s normal for you and to raise any concerns with your doctor.

Other causes of menstrual irregularities

If you experience irregular periods, it may not be down to birth control. There are a great many other factors that could affect your cycle, including:

  • Having high-stress levels.
  • Extreme weight loss.
  • Over-exercising.
  • Pelvic inflammatory disease: PID is an infection of the reproductive system, which can cause heavy or long periods, spotting between periods and abdominal pain.
  • Endometriosis: This condition, which affects 10% of women, causes the tissue that usually lines the uterus to grow outside the uterus. Endometrial tissue can cause prolonged bleeding as well as other symptoms like cramps and back pain.
  • Polycystic ovary syndrome (PCOS): This condition often causes sufferers to have high levels of insulin and male hormones, called androgens. These can prevent ovulation and cause irregular periods. People with PCOS might have fewer periods, or they may stop having periods completely.
  • Perimenopause: As your body begins to make the transition into menopause, you may experience longer periods.

How heavy should a period be?

The heaviness of your menstrual flow depends on lots of different things, from how thick your uterine lining is to your hormone levels. 

Typically, women will lose a small amount of blood over the course of their period - only 2 to 3 tablespoons. However, it can be difficult to measure how much blood you’re losing, and everyone has a different perception of what a heavy period means.

Some indicators that you might have heavy periods include:

  • If your periods last for 7 or more days
  • If you need to change your pad or tampon every hour or two, or need to empty your menstrual cup frequently throughout the day
  • If you need to use two types of period products at once, like a pad and a tampon together
  • Bleed through your period products to your clothes or bedding
  • Pass blood clots that are larger than an inch or 2.5 centimeters

It could be normal for you to have heavy menstrual bleeding, but it could also be a symptom of another condition such as PCOS, endometriosis, PID or fibroids. It could also be a side effect of certain medications and treatments.

You may also experience heavy bleeding if you have depression or high stress levels. Again, it’s important to know what’s normal for your body. Heavy bleeding can interfere with your everyday life - but you shouldn't have to suffer through it. If you’re concerned about anything, speak to your healthcare provider straight away.

Bleeding between periods

Many women experience bleeding or spotting between periods. It may be normal, but there also some factors that could be causing abnormal bleeding between periods, including:

  • Hormonal contraceptives: Many women experience irregular periods when on hormonal contraceptives, particularly during the first few months
  • Taking the emergency contraceptive pill
  • If you’ve recently had an abortion
  • If you’ve recently had a miscarriage
  • Sexually transmitted infections like chlamydia
  • Vaginal dryness
  • An injury, such as from penetrative sex
  • Hormonal imbalance
  • Cancers: Cervical cancer, womb cancer, and vaginal cancer can all cause irregular periods
  • Fibroids

If you’re concerned about irregular periods, speak to your healthcare provider. They may offer you an STI test, a pregnancy test, a pelvic exam, a cervical screening test, or pelvic ultrasound, depending on your symptoms and circumstances.

How to keep track of your menstrual cycle

The only way to find out what’s normal for your cycle is to keep track of it. Over time, you’ll start to understand what’s normal for your body, and you’ll be better able to spot any menstrual irregularities. 

You can track your periods in the Natural Cycles app, which will help you to see how long your menstrual cycle lasts and whether your period lasts for roughly the same number of days every month. You may also want to keep track of:

  • How heavy your flow is
  • Whether you have any abnormal bleeding between periods
  • Any pain you get with your period
  • Any other changes in mood, behavior, or any other symptoms

We’ve designed the Natural Cycles app so you can learn more about your body and your menstrual cycle, helping you to understand your cycle length, the average duration of your periods, and what is considered normal for you.

When you sign up, you’ll have access to all of our features including NC° Birth Control and NC° Plan Pregnancy, and you’ll also be able to track how you’re feeling and note down any symptoms you experience. Why not find out if Natural Cycles could work for you today?

Did you enjoy reading this article?

Natural cycles logo

Ready to get started?

Featured Posts

Period & Bleeding

11 Signs your period is coming

11 min read

Period & Bleeding

What does the color of period blood mean?

9 min read

Sex & Pleasure

Different types of sex & sexual acts: Oral, anal defined

9 min read

Keep reading...