Vaginal Bleeding and Spotting Between Periods: Causes and When to See a Doctor

Noticing some blood in your underwear before or after your period is due can be worrying, but it’s more common than you may think, and in many cases, isn’t usually a sign of anything serious. Common causes of spotting between periods include hormone changes, contraception use and ovulation, but whatever the cause may be, it’s always best to get new or unusual bleeding checked to rule out any underlying issues.

In this guide, we’ll explain what spotting or bleeding between periods might look like, the common causes, how it is diagnosed and treated and when you should speak to a clinician for more advice. 

What Counts as Bleeding or Spotting Between Periods?

Spotting or bleeding between periods, also known as intermenstrual bleeding, is any vaginal bleeding that occurs outside of your usual menstrual cycle.* Spotting is usually lighter than your normal period and may appear as pink, red or brown staining in your underwear. Some women may never experience spotting, others may get it once or twice, and others may notice it more regularly, such as around ovulation. 

* Rao, S. (2011). Intermenstrual and post-coital bleeding.

What doesn’t count as bleeding or spotting between periods?

A typical menstrual cycle can last between 21 and 35 days, with a period or bleed lasting 2 to 7 days.* If your cycle is shorter than 21 days or longer than 35 days, this is known as an irregular cycle rather than bleeding or spotting between periods. Your clinician can help you find out what may be causing an irregular cycle. 

If you notice light brown or pink blood a few days before your period is due to begin or for a couple of days afterwards, this is part of your usual period and does not count as spotting. 

* NHS. (2023). Periods. 

What Causes Bleeding or Spotting Between Periods?

For most women, bleeding or spotting between periods isn’t a cause for concern, with up to ⅓ experiencing it in their lifetime.* There are several possible causes ranging from hormone changes, hormonal contraception and pregnancy to conditions such as polyps, fibroids, and adenomyosis. In some cases, spotting can indicate a more serious condition, so it is always best to get any new or unexplained bleeding checked out by a clinician.

Clinicians sometimes organise causes of abnormal uterine bleeding using the PALM–COEIN framework.** PALM covers changes to the structure of the womb:

• Polyps

• Adenomyosis

• Leiomyomas (fibroids)

• Malignancy or endometrial hyperplasia (a thickened womb lining)

COEIN covers: 

• Coagulation problems

• Ovulatory dysfunction

• Endometrial causes

• Iatrogenic causes such as medications or contraception

• Not otherwise classified

That framework is useful, but it is not a checklist you need to use on your own. It describes bleeding from the womb, but a clinician will also consider bleeding from the cervix or vagina, infections and pregnancy-related causes.

* Mikes, B. A. et al. (2025). Abnormal uterine bleeding.

** Madhra, M. et al. (2014). Abnormal uterine bleeding: advantages of formal classification to patients, clinicians and researchers. 

Structural causes

Some of the potential structural causes of spotting between periods include:

• Polyps are growths in the lining of the womb or on the cervix. They are usually harmless and not cancerous, but may cause spotting between periods or bleeding after sex. Depending on their location and your symptoms, a clinician may recommend an ultrasound or a closer look inside the womb.

• Fibroids are non-cancerous muscle growths in or around the womb. They are more often associated with heavy or prolonged periods, though bleeding between periods can also happen.

• Adenomyosis develops when tissue from the womb lining grows into the womb’s muscular wall. Painful, heavy periods are typical symptoms,* and some people also report bleeding between periods. It is different from endometriosis, although the two conditions can occur together. Find out more in our adenomyosis versus endometriosis guide.

• Endometrial hyperplasia is when your womb lining becomes unusually thick.** Changes to the lining, and less commonly cancer of the womb or cervix, can cause unexpected bleeding. Most people with spotting do not have cancer. Still, bleeding between periods or after sex should be checked so that a cause needing treatment is not missed.

* NHS. (2023). Adenomyosis. 

** Royal College of Obstetricians and Gynaecologists. (No date). Endometrial Hyperplasia. 

Non-structural (hormonal and functional) causes

In most cases, spotting between periods is harmless and caused by changes in your hormone levels.

Ovulation and hormone fluctuations

You may notice a small amount of bleeding around ovulation, sometimes with one-sided lower abdominal pain, but it isn’t common, with around 4.8% of women reporting mid-cycle bleeding.*

Hormone shifts can also make your period timing less predictable. For example, polyendocrine metabolic ovarian syndrome (PMOS) can make ovulation infrequent or unpredictable. Periods may be far apart, and bleeding can be irregular or sometimes heavy. Perimenopause, on the other hand, can make ovulation less regular, and the time between periods may change. That can make spotting more noticeable. A one-off spot at mid-cycle may have a straightforward explanation, but recurring or unfamiliar bleeding still warrants a conversation with your GP.

* Dasharathy, S. S. et al. (2012). Menstrual Bleeding Patterns Among Regularly Menstruating Women.

Hormonal contraception

Breakthrough bleeding can happen after starting or changing a pill, implant, injection or hormonal coil. It often settles as your body adjusts, though some methods can cause irregular bleeding for longer. Missed pills and taking medications that affect contraception may also change your bleeding pattern. If bleeding persists, begins after a previously stable pattern, follows sex or comes with other symptoms, ask a clinician to review it. If you forget to take a pill, check the patient information leaflet to find out what you should do. 

Infections

Sexually transmitted infections (STIs), including chlamydia, and pelvic inflammatory disease can cause bleeding between periods or after sex. Unusual discharge, pain during sex, pelvic pain or fever make an infection more important to rule out. If you have had unprotected sex, consider getting an STI test to rule out an infection as the cause of your bleeding between periods.

Pregnancy

Light spotting can occur in early pregnancy, especially around the time of implantation, but bleeding alone cannot tell you whether you are pregnant or why it is happening. If pregnancy is possible, take a test at the appropriate time. Contact your doctor or midwife if you have any bleeding during a confirmed pregnancy. A missed period followed by unusual bleeding and abdominal or pelvic pain also needs urgent assessment because it could be an ectopic pregnancy.

Other causes

Sometimes a condition affecting how your blood clots, a medication such as an anticoagulant, or changes in how the womb lining responds to hormones may contribute to spotting. Vaginal dryness or irritation can also cause light bleeding, particularly after sex due to friction or a lack of arousal. 

Other Signs and Symptoms That Can Occur Alongside Spotting

There are so many potential reasons why you may be experiencing spotting or bleeding between periods that it can be hard to pinpoint the cause yourself. You may notice only spotting, or you may also have 1, 2, or a few accompanying symptoms. Keeping a symptom diary can help your clinician narrow down potential causes and choose the most appropriate tests.

Here’s what bleeding between periods and these symptoms could mean:

These are patterns, not a diagnosis. For example, pelvic pain and bleeding can have several causes, including pregnancy-related problems, if pregnancy is a possibility. Tell your clinician about any undiagnosed or new bleeding between periods so they can determine the true cause.

How Is Bleeding or Spotting Between Periods Diagnosed?

Diagnosis can be daunting, especially if you are unsure about what to expect. It’s easy to think you’ll need the most invasive tests straight away, but that's usually not the case. Your first appointment often focuses on understanding your symptoms, including your bleeding pattern, so your clinician can decide which checks will be most useful. 

They may ask when the bleeding began, when it happens during your cycle, how much blood is present and if it happens during or after sex. They may also ask about contraception, medications you take, if you could be pregnant, any pain or discharge you have and your sexual history. Don’t be alarmed; these are routine questions that can help narrow down potential causes. 

Once these have been discussed, the potential next steps might include:

• A pregnancy test, even if you use contraception, if pregnancy is possible.

• STI tests, particularly if you are also experiencing discharge, pain or bleeding after sex.

• Blood tests, such as a full blood count if bleeding is heavy, or selected tests when your history suggests a thyroid or hormonal issue.

• An examination, sometimes including a speculum examination to look at the vagina and cervix. You can ask what will happen before agreeing to an examination.

• A pelvic ultrasound to look for changes such as fibroids or some polyps.

• A hysteroscopy, which uses a small camera to look inside the womb, and sometimes an endometrial biopsy to examine a sample of its lining.

You likely won’t need every test. Your age, symptoms, medical history and examination findings will help guide the choice, but your clinician will keep you informed at every point during the diagnosis process. If you feel uncomfortable at any point, you can ask the clinician to stop or ask for further clarification. You can also request a chaperone for certain examinations or bring someone you trust to your appointment, whatever makes you feel at ease.

What Are the Treatment Options?

The right treatment for you will depend on the cause, how much the bleeding is affecting your daily life and whether you want to become pregnant. In some cases, you may not need any treatment at all, while simple options, such as reviewing your current contraception, could be enough to resolve the issue. If testing identifies an underlying condition, your GP will discuss appropriate treatments with you. 

Some treatments could include:

• Hormone therapy to help regulate or reduce bleeding. Options could include the combined contraceptive pill, a mini pill or a hormonal coil. The right choice depends on your current health, preferences, and pregnancy plans.

• Antibiotics if testing identifies an STI as the cause. Your clinician will explain whether sexual partners also need testing or treatment. 

• Surgery for structural causes such as a polyp or fibroids, depending on their size, position and symptoms.

• Supportive care can help while you are waiting for a diagnosis. Keeping a symptom diary can help identify and describe any changes in your bleeding pattern.

When to see a doctor for spotting between periods?

Spotting between periods is common and often has a harmless explanation, but any new or unexpected bleeding, bleeding during or after sex, heavy or prolonged bleeding or bleeding that causes you any concern should be investigated by a clinician. 

If the bleeding is very heavy and you feel faint, weak or show signs of shock, or have severe abdominal pain, chest pain or collapse, call 999 or get someone to take you to A&E.

You don't need to decide whether spotting is enough to justify asking for help. If it is unusual for your body, a GP can help you find out why, no matter how small you feel it may be.

FAQs

Is occasional spotting between periods normal? 

No. Occasional spotting can have many causes, including hormonal changes during ovulation or starting a new hormonal contraceptive. However, any bleeding outside your usual cycle is usually irregular and should be discussed with your doctor to rule out underlying causes. 

Can stress cause spotting between periods? 

Yes. If you are physically or emotionally stressed, it can cause breakthrough bleeding or light spotting between periods. During stressful times or situations, your hormones can become imbalanced, causing a small amount of your womb lining to be shed early, which can cause unexpected bleeding or spotting between periods. You should make an appointment with your GP if stress is causing spotting, so that they can rule out any other potential causes and provide further support if you would like it. 

Does spotting mean I'm pregnant? 

It depends. Light spotting, also known as implantation bleeding, can be an early sign of pregnancy. It happens when a fertilised egg implants into the lining of your womb, causing a small amount of the womb to shed. Implantation bleeding usually occurs 10 to 14 days after conception, usually around the same time that your period is due, meaning you may confuse it for a light period. However, spotting can have many causes, so speak to your GP if it happens. 

Can hormonal contraception cause spotting? 

Yes. Hormonal contraception is a very common cause of spotting or breakthrough bleeding, especially when you first start using it.* If your bleeding pattern does not settle down after 3 months, you should contact your clinician, who can check for other possible causes of spotting.

* NHS. (2024). Side effects and risks of the combined pill. 

Is spotting between periods more common during perimenopause? 

Yes. Spotting or irregular bleeding between periods is common during perimenopause because of your changing hormone levels, but should always be checked by a clinician.

Can PCOS or endometriosis cause bleeding between periods, and what can I do about it?

Yes. Both polyendocrine metabolic ovarian syndrome (PMOS), formerly known as PCOS, and endometriosis can cause irregular bleeding or spotting between periods. PMOS is associated with hormone imbalances that can prevent regular ovulation, leading to unpredictable cycles, missed periods or light spotting. Endometriosis is when womb-like tissue grows outside of the uterus, which can cause heavy periods, prolonged bleeding and spotting between periods. 

If you suspect you may have either condition, keep a symptom diary, noting any pain you feel, when the bleeding occurred, and how much blood there was. This can help your clinician decide if you may need further tests and which treatment options may be most suitable for you.