Why Is My Period So Light This Month? 10 Reasons For Light Period

Are you worried why period is very light this month? Do you feel signs of pregnancy or afraid you may have a medical problem? Early very light period could be a sign of pregnancy, peri-menopause or minor effects of unstable hormones.

This article will explain the causes of less bleeding during periods and when to worry. Normal menstrual cycles can vary a lot from woman to woman, so a “light” period is not always dangerous, but sometimes it needs to be checked. 

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What is a normal period and when is a period light?

If you just started menstruating for the first time, you may be worried about how long period last. Period normally last between 2 – 7 days, and most girls start menstruating between ages 11 and 14. Doctors usually advise a check-up if there is no period by age 15 or more than 3 years after breast development starts. MedlinePlus+1

Period lasting more than seven days is prolonged while period lasting less than two days is short.

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How much blood is lost in each period?

Normal blood loss during period is usually around 30 – 40 mls, and doctors often consider anything from about 5 – 80 mls per period to be within the normal range. NCBI If your period blood loss is more than 80mls and this keeps happening, your period may be abnormally heavy.

However, if your period blood loss is very small (often described as just light spotting or only a few drops on your pad or tampon), then you have a very light period. In medical terms this is sometimes called “hypomenorrhea”. A light period may mean there is a medical problem, pregnancy or unstable hormones, but in some women it is just normal for them.

Remember it is very hard to measure blood in mls at home, so how often you change pads, tampons or menstrual cups and how you personally feel about the flow is more practical than exact numbers.

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Why is my period so light this month?

If you had a light period and worried, these are the common causes.

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1. Pregnancy

Pregnancy is one possible cause of very light period in women. Spotting before period may be confused as lighter than normal period. In early pregnancy this light spotting can sometimes be due to implantation bleeding.

What is implantation bleeding and when does it occur?

After intercourse during your fertile window, fertilization may occur. Fertilization is the union of the man’s sperm and the woman’s ovum. After fertilization, the zygote or fertilized egg is implanted into the lining covering the uterus (endometrium). During this process called implantation, slight bleeding that occurs in some women may be confused as a very light period. Not every pregnant woman will have implantation bleeding.

How long does implantation bleeding last? Implantation bleeding usually lasts for a few hours to a maximum of 2–3 days, and it is usually a brownish or pinkish discharge before period.

What should I do if my very light period is due to pregnancy?

If you notice a very light period that is earlier than normal, it may be due to implantation bleeding. However, there are many other reasons for early period.

If due to pregnancy, you should wait for a while and get a home pregnancy test. Most modern tests can detect pregnancy from the first day of a missed period if you use them correctly. If you check for pregnancy very early (for example, the same day as the light spotting), it may be negative due to low HCG levels. If your period is late, test, and the result is negative, repeat the test in about one week or see your doctor if you are still not sure. nhs.uk

If you have light bleeding plus severe one-sided lower tummy pain, shoulder pain, dizziness or fainting and you might be pregnant, you should see a doctor or go to the emergency room urgently to rule out ectopic pregnancy.

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2. After your first period or years before menopause

If you are less than 20 years or more than 40 years, then its possible you may have very light periods sometimes.

In young girls, periods after menarche (first period) are usually lighter than normal or may be irregular.

As you grow older, especially in the first few years after your first menstruation, your body hormones will normalize and your cycle often becomes more regular. So, if you are worried about your very light period after your first period (menarche), then you shouldn’t, as long as you are otherwise well and not bleeding heavily or missing periods for many months.

Women more than 40 years and close to menopause may experience irregular period that is shorter than normal or lighter than normal. This can be normal as it’s common for period to get irregular and lighter as you get closer to menopause (perimenopause). nhs.uk

During menopause, your period stops. If you’ve stopped having period for 12 consecutive months and notice light bleeding from your vagina, then it’s abnormal. You should inform your doctor as bleeding after menopause must always be checked, because in a small number of women it can be a sign of cancer of the womb, although there are also harmless causes. MedlinePlus

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3. Weight loss or obesity

If you are obese, it’s possible you may have a very light period or irregular period. Some women with obesity have heavier bleeding, while others have very irregular, sometimes light periods because they are not ovulating regularly. nhs.uk

Excessive exercise and severe weight loss can affect hormones that control your menstrual cycle. In extreme cases, your period can stop completely (amenorrhea).

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4. You are on birth control pills

If you are on a birth control pill or missed a pill, then it’s possible you may have very light bleeding or spotting in between periods. Birth control pills work to prevent your ovulation. If you do not ovulate, then you cannot get pregnant.

Ovulation is the release of an egg from the ovaries. If ovulation does not occur, the covering of your womb (endometrium) will be thin. This can come out like a light period in women.

Other hormonal methods like the contraceptive injection, implant or some hormonal IUDs can also make your period very light or stop altogether, and this can be normal for those methods. nhs.uk

What should I do?

If you have a light period after missing your pills for days, it may be due to hormonal changes or pregnancy.

Do you feel pregnancy signs like nausea, body weakness or increased urination?

Also, if you have just started taking a pill, then it’s okay if you experience some light spotting. This resolves in few months time as you body adjusts to these pills.

Excessive bleeding with blood clots while on pills are abnormal. You should talk to your doctor ASAP, especially if you also feel dizzy, breathless or very tired.

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5. You have Eating Disorders

Eating very little food (Anorexia nervosa) or eating too much food without control (Bulimia nervosa) can affect your period.

Eating problems can affect the hypothalamus pulse release of hormones that stimulate the pituitary gland and ovaries to secrete estrogen and progesterone. For normal period to occur, there is an interplay between estrogen and progesterone hormones.

Eating disorder in women may cause early menstruation, no period or very light period. These are serious medical and mental health problems, so you should always seek help from a doctor or mental health professional if you suspect an eating disorder.

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6. Polycystic ovarian syndrome (PCOS)

Women with polycystic ovaries may sometimes have an irregular light period or heavy period.

What is PCOS? This is a common cause of infertility among women of childbearing age and occurs due to hormone imbalance.

Symptoms of PCOS are

• Excessive body hair distribution

• Polycystic-appearing ovaries on ultrasound

• Difficulty conceiving

• Weight gain or obesity

• Heavy or light periods, or long gaps between periods

• Spotting after period

• Acne

What should I do if I have these symptoms and light periods?

You should inform your doctor and try to lose weight if you are overweight. PCOS is linked to long-term risks like diabetes and high blood pressure, so proper diagnosis and follow up is important. Mayo Clinic+1

Drugs like clomiphene, combined oral contraceptive (COC) pills and metformin are used in women with PCOS to regulate period and improve fertility, but they should only be taken when prescribed and monitored by your doctor. You can read more on Mayo Clinic – Polycystic ovary syndrome (PCOS). Mayo Clinic

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11 Reasons to worry about very light periods?

• You continue to have very light period years after menarche

• You are finding it difficult to get pregnant

• Your period is too frequent and lasting less than two days

• You notice your period every less than 21 days

• Your period is very irregular

• You feel vaginal itching or pain during intercourse (This may be an infection)

• Your period blood loss in less than 20mls (scanty period)

• You’ve had no period for three months

• Bleeding after menopause

• You feel a mass in your abdomen, or your tummy is getting bigger in size.

• You feel pregnant

• You have very light bleeding with severe lower tummy pain, dizziness or fainting, especially if you may be pregnant.

Many of these situations fit what doctors call abnormal uterine bleeding, which should be checked by a health professional. See more on ACOG – Abnormal Uterine Bleeding. ACOG+1

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Frequently asked questions about light period flow in women

These are some FAQs about light period flow that may concern you. Let us know if you have more questions below.

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Light period, Am I Pregnant?

If you notice light period that is earlier than normal, then it could be due to pregnancy, especially if you had unprotected sex. Implantation spotting usually occurs about 6–12 days after you ovulate, often 4 days to a week before your next period. It is lighter than your period and usually does not last more than three days.

Other causes of light periods are

• Trauma during intercourse

• Infections

• PCOS

• Excessive weight loss

• Young women after menarche

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Why is my period lighter than normal this month

If you are just noticing a lighter than normal period this month then its possible due to pregnancy. Do you feel other pregnancy signs — nausea, getting tired easily and cramps?

Other reasons your period is lighter than normal are

• Stress

• weight loss

• Eating disorders

• Obesity

• Polycystic ovaries

• birth control pills

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Is light period brown blood pregnancy? Is it unusual?

Yes and No. Unusually light period brown blood may be due to pregnancy. Implantation blood is a light or brown discharge that comes out from your vagina some days before your period. You should wait for some time to get a pregnancy test done.

Other causes of light period brown blood are

• Old blood from your last period slowly coming out

• Vaginal infection

• Birth control pill

• Ovarian cyst

Read more: Why is my period blood black or dark?

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What causes Light period negative pregnancy test?

Light period with negative pregnancy test may be due to other non-pregnancy reasons or pregnancy too. If your light period is due to implantation, pregnancy test done on the day of implantation will be negative and inaccurate. If your pregnancy test is negative and you have light spotting, then you should wait for a week and recheck again.

If your test is still negative one week after your missed period and you used the test correctly, pregnancy is unlikely and your light period may be due to:

• Birth control pills

• vaginal infections

• Stress

• Eating disorders

• Uterine fibroid

• Excessive exercise and weight loss

• Polycystic ovaries

• Other hormone problems like thyroid or prolactin disorders

For more information on unusual vaginal bleeding you can see MedlinePlus – Vaginal or uterine bleeding. MedlinePlus

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Now it’s your turn. Do you have lighter than usual period? Is this the first time? Are you worried it could be pregnancy? Let us know below.

You can read more about normal menstrual cycles on MedlinePlus – Menstruation. 

You can read more about irregular periods around puberty and menopause on the NHS – Irregular periods page. 

This article is for general education only and does not replace seeing your doctor or nurse. Always get checked if you are worried about your symptoms.