The short answer: A day or so of light brown spotting just before your period is common and usually just your period starting slowly. Spotting that starts several days before each period, or is new for you, can point to low progesterone after ovulation, hormonal contraception, perimenopause, PCOS, thyroid problems, polyps, fibroids, endometriosis or early pregnancy. Track it for two or three cycles and see a doctor if it keeps happening, lasts more than a couple of days or comes with pain or bleeding after sex.
What counts as spotting before your period?
Premenstrual spotting is light bleeding in the days before your period properly starts. It is usually brown or dark red, and often shows up as a smear on toilet paper or a small mark on your underwear. It does not need a full pad.
It is different from your period itself. A period has a steady flow that needs a pad, period panty, tampon or cup, and the NHS says it usually lasts about 5 days, anywhere from 2 to 7. Spotting is a few drops here and there.
Brown is the most common colour because the blood is older. It has left the womb slowly, so it has had time to darken. Brown Discharge and Brown Period Blood: What It Means explains why blood changes colour.
If your bleeding comes back a few days after your period has finished, that is a different pattern. Bleeding Again After Your Period Ended? What It Means, by Timing covers it.
What's normal: a day of brown spotting
For many women, a period doesn't switch on all at once. The lining of the womb starts to loosen, a little old blood comes out first, and then the flow begins within a day. That brown smear the morning before your period is very common and nothing to worry about.
Signs that your spotting is probably just the start of your period:
- it happens a day, or at most two, before the flow
- it happens at about the same point most months
- it turns into your usual period, with your usual amount of bleeding and cramps
- your cycles are between 21 and 35 days long, which the NHS describes as common
Spotting that starts three, five or seven days before the period, gets longer over time, or appears suddenly after years of clean starts is worth looking into. So is spotting that comes and goes without a period following.
Why spotting before a period happens
After you ovulate, the empty follicle in the ovary makes progesterone. Progesterone keeps the thickened womb lining stable for the second half of the cycle, called the luteal phase. If no pregnancy starts, progesterone falls and the lining sheds as your period.
If progesterone is lower than usual, falls early, or the lining doesn't respond to it well, small parts of the lining can start breaking down before the full period. That shows up as spotting. Hormonal medicines, growths in the womb and changes on the cervix can also cause bleeding in these days, for different reasons. The Hormones Behind Your Menstrual Cycle, Phase by Phase explains the hormone side in more detail.
Causes of spotting before your period
Low progesterone or a short luteal phase
Cleveland Clinic says the luteal phase usually lasts about 12 to 14 days, from ovulation until your period. A short luteal phase means your period starts within 10 days of ovulation. When the ovaries don't make enough progesterone after ovulation, or the lining doesn't respond to it, it is called a luteal phase defect.
Cleveland Clinic lists spotting between periods and cycles shorter than 21 days among its possible signs. Many people only find out about it when they have trouble getting pregnant. Linked factors include stress, very intense exercise, obesity, eating disorders, thyroid problems, PCOS and endometriosis. Experts don't fully agree on how to diagnose it, so your doctor will look at the whole picture.
Hormonal contraception
The NHS lists hormonal contraception, such as the pill, as a common cause of bleeding between periods. Spotting is more likely in the first few months of a new pill, implant, injection or hormonal coil, and if you miss pills or take them at different times. A copper coil can also make periods heavier and bring some spotting around them, especially early on.
Perimenopause
In the years before menopause, usually in your 40s, ovulation becomes less regular and hormone levels swing. Spotting before periods, shorter or longer cycles and heavier periods are all common. Perimenopause: Symptoms, Period Changes and What Helps explains what is typical.
PCOS
Polycystic ovary syndrome can stop you ovulating regularly. Without regular ovulation there is less progesterone, and periods can arrive late, with days of brown spotting first. Other signs include acne, extra facial or body hair and cycles often longer than 35 days. Read PCOS Explained: Symptoms, Diagnosis and Treatment.
Thyroid problems
Both an underactive and an overactive thyroid can unsettle your cycle and the hormones that control it. Thyroid problems are easy to check with a simple blood test. See Thyroid and Your Periods: How Thyroid Problems Affect Your Cycle.
Fibroids and polyps
The NHS lists small growths in or around the womb, such as polyps or fibroids, as causes of bleeding between periods. Polyps are small, usually non-cancerous growths of the womb lining or cervix. Fibroids are non-cancerous growths of muscle in the womb, and can also make periods heavier or longer.
Endometriosis
Endometriosis is when tissue similar to the womb lining grows outside the womb. It is best known for painful periods, but some women also notice spotting before their period. It is also among the conditions linked with a short luteal phase. See Endometriosis: Symptoms, Diagnosis and Treatment.
Early pregnancy
Implantation bleeding happens when a fertilised egg attaches to the womb lining. Cleveland Clinic says it usually happens about 10 to 14 days after ovulation, close to when your period is due, and that about 1 in 4 pregnant women have it. It is pink, brown or dark brown, very light, and usually stops within about two days without turning into a flow.
Infection and cervical changes
Infections such as chlamydia, and harmless changes on the surface of the cervix, can cause spotting at any time, including just before a period. These are more likely if the spotting follows sex. Read Brown Spotting After Sex: Common Causes and When to Get Checked.
Normal or worth a check? A quick guide
| What you notice | What it often means | What to do |
|---|---|---|
| Brown spotting for a day, then your period | Your period starting slowly | Nothing; this is common |
| Spotting for 3 or more days before most periods | Possible low progesterone, polyps, fibroids or endometriosis | Track for 2 to 3 cycles, then see a doctor |
| Spotting in the first months of a new contraceptive | Common side effect of the method | Give it time; see a doctor if it continues or is heavy |
| Spotting around when your period is due, then no period | Possibly implantation bleeding | Take a pregnancy test once your period is late |
| Spotting with cycles shorter than 21 days | Possible short luteal phase or other hormone change | See a doctor |
| Spotting with irregular or very long cycles, acne or extra hair | Possible PCOS | See a doctor for tests |
| Spotting in your 40s with changing cycles | Often perimenopause | See a doctor to rule out other causes |
| Spotting with pain, smell, unusual discharge or after sex | Possible infection or cervical cause | See a doctor soon |
Could spotting before your period be pregnancy?
It could, if you had unprotected sex in that cycle. The clue is what happens next. Premenstrual spotting turns into a period within a day or two. Implantation bleeding stays very light and stops, and the period doesn't come.
Cleveland Clinic notes that a home pregnancy test can still be negative this early, because the pregnancy hormone may not yet be high enough. For the most reliable result, wait until your period is late. If the test is negative but your period still hasn't come a week later, test again. Can You Have a Period While Pregnant? explains why bleeding in early pregnancy is easy to confuse with a period.
If you are pregnant and have any bleeding, get advice from your doctor the same day.
How to track premenstrual spotting
A short record helps you see whether your spotting is a one-off or a pattern, and makes your doctor's visit much more useful. Use a period app, your phone's notes or a diary.
Write down:
- the first day of each period (day 1 of your cycle)
- the days you spot, the colour and roughly how much
- how many days the spotting comes before the flow
- pain, discharge changes, sex and any change to contraception
- if you track ovulation, the day of your positive LH test or temperature rise
A worked example: Anjali's period starts on 5 July and then on 2 August, a 28-day cycle. She notices brown spotting on 29, 30 and 31 July and 1 August, four days before her flow. In August and September the same thing happens. Four days of spotting before every period is longer than the usual day or so, and it is worth showing her notes to a gynaecologist.
If she has also been tracking ovulation and sees her period arrive only 9 or 10 days after it, that hints at a short luteal phase. That is useful detail for her doctor, especially if she is trying for a baby. For help with counting, see How to Calculate Your Next Period Date (With Examples).
Tests a doctor may do
Your doctor will ask about your cycle length, how many days you spot, contraception, pregnancy plans and other symptoms. The NHS says a doctor or nurse may suggest a pregnancy test, blood tests, an STI test and an examination of the vagina and cervix. Depending on your answers, the tests may include:
- Pregnancy test: to rule out early pregnancy.
- Hormone blood tests: Cleveland Clinic says progesterone, FSH, oestrogen and LH may be checked when a luteal phase problem is suspected. The timing in your cycle matters, so follow your doctor's instructions on which day to go.
- Thyroid tests: a simple blood test.
- Haemoglobin: if your periods are also heavy, to check for anaemia.
- Swabs: to look for infections such as chlamydia.
- Pelvic ultrasound: to look for fibroids, polyps, ovarian cysts or signs of PCOS, and to measure the womb lining.
- Cervical screening: if you are due.
Further tests, such as a hysteroscopy, where a thin camera looks inside the womb, are sometimes suggested if a polyp or a lining problem is suspected. Treatment depends on the cause. It might be a change of contraception, treating PCOS or a thyroid problem, removing a polyp, or, if you are trying to conceive, hormone support that your doctor may suggest.
Staying comfortable on spotting days
For a day or two of brown spotting, a panty liner is usually all you need. It also lets you see the colour and amount for your notes. Fabpad's disposable liners are fragrance-free, which helps if your skin reacts to scented products.
If you never know whether today is a spotting day or the first day of your period, a period panty covers both on its own. Fabpad period panties have one absorbency for every flow, from spotting to heavy days, and can be worn for up to 8 hours depending on flow. More ideas are in What to Wear on Spotting Days: Liners, Period Panties and More.
When to see a doctor
See a doctor if
- you spot for more than two days before most periods
- premenstrual spotting is new for you or is getting longer
- your cycles are often shorter than 21 days or longer than 35 days
- you also have very painful or heavy periods
- you have bleeding after sex, unusual discharge, a bad smell or pelvic pain
- you are trying to get pregnant and spot before every period
- you have any bleeding after menopause
Get urgent help if
Call 112 or 108, or go to the nearest hospital emergency department, if you could be pregnant and have bleeding with severe tummy pain, pain on one side, shoulder-tip pain, dizziness or fainting. These can be signs of an ectopic pregnancy. Also get urgent help for bleeding that soaks a pad within an hour.
Frequently asked questions
Is it normal to spot a day before my period? Yes. A day of brown spotting before your flow is very common and usually just your period starting.
Why do I spot a week before my period? A week is longer than usual. It can be linked to low progesterone, contraception, polyps, fibroids, endometriosis or perimenopause. Track it and see a doctor if it repeats.
Is spotting before my period a sign of pregnancy? It can be, if your period then doesn't come. Take a pregnancy test once your period is late.
Does premenstrual spotting mean I can't get pregnant? Not necessarily. Many women who spot get pregnant without trouble. If you have been trying for a while, mention the spotting to your doctor.
Can stress cause spotting before my period? Stress is linked with hormone changes that can affect your cycle. Still, don't put repeated spotting down to stress without a check-up.
Can thyroid problems cause spotting? Yes, thyroid problems can unsettle your cycle. A simple blood test can check.
Is brown spotting before a period a sign of infection? Usually not. Brown simply means older blood. Spotting with a bad smell, itching or unusual discharge needs a check for infection.
Related reading
- Ovulation Spotting: Why You Bleed Mid-Cycle and When to Worry
- What a Healthy Period Looks Like: Flow, Colour, Length and Symptoms
- Period Came Early? 9 Reasons and When to Worry
- Irregular Periods: Causes, Tests and What Helps
This article is for general information and doesn't replace advice from your doctor.
Sources: NHS: Vaginal bleeding between periods or after sex, NHS: Periods, Cleveland Clinic: Luteal Phase Defect, Cleveland Clinic: Implantation Bleeding