How late can a period be before you should start to worry?

What is considered a late period?

The average menstrual cycle lasts about 28 days. But it's common for women to have a slightly shorter or longer cycle than this. This means that a woman’s menstrual cycle can fall anywhere within 21 to 38 days.

Your period can last for 3 to 8 days, and bleeding tends to be heaviest in the first 2 days.

It can take a few months to a few years to establish a regular cycle when you start getting your period for the first time. Some women always have irregular periods, where their menstrual cycle varies from month to month.

Keeping track of periods can help you to establish the length of your cycle, helping you to identify any irregularities. Some smartphone apps make tracking easier. Knowing when to expect your period will help you recognize if your period is late. Often periods are 2 to 3 days late with cycle fluctuations.

Many women consider their period as late if it hasn’t started within 5 or more days after their expected start date. It’s difficult to give a conclusive timeframe of what is considered to be a late period, as cycles vary amongst women. For example, if your period is always on time, every month, then a period which has not come within 2-3 days of when it is expected, would be considered late for that person. If your period is slightly irregular, and you are often 2-3 days early or late, then being a few days late is neither here nor there. The general consensus is that if your period is late by up to 5 days, there isn’t usually cause for concern as yet. So, if you haven’t started your period before this time frame, it wouldn’t be considered as “late”. However, you need to be aware of your cycle, as only you will know what isn’t normal. 

How late can a period be without being pregnant?

How late a period can be without being pregnant depends on the regularity of your periods.

Generally speaking, if you are 1-2 days late it is not usually anything to worry about. If it is 3 days late and this is not normal, you will probably start to worry. At 5 days late, you are probably convinced that you’re pregnant – it’s probably a good idea to do a pregnancy test at this stage. If you are 7 days late with no pregnancy symptoms, it still doesn’t necessarily mean that you are pregnant (it can, but it’s not always the case… take a test, another one).

However, if you have a late or missed period with early signs of pregnancy, this is a strong indication of pregnancy. The scales are tipping more in favor of “pregnant”, than “not pregnant”. Symptoms of early pregnancy include cramps, deep tiredness, tender breasts, needing to wee more often, feeling nauseous and/or being sick, mood swings, a metallic taste in your mouth and food cravings. If you think you might be pregnant you should take a pregnancy test.

I’m not pregnant so why have I missed my period?

The most common assumption for a missed period is pregnancy. But if there's no way you're pregnant or your pregnancy test is negative, what else could be the cause of your missed period? There are a number of other reasons that could explain why you’ve missed your period.

Other reasons for a late period if you are not pregnant include:

Stress

Stress is the most common cause of irregular periods and can even cause a missed period.

Prolonged periods of stress such as a high-pressured job can affect your menstrual cycle. Other example of stress factors such as the death of a loved one, exams, job loss and major life events can interfere with your body’s delicate hormone balance. It’s not just emotional stress that can affect your periods, but physical stress too. Recent illness, surgery and medical conditions such as diabetes can also delay periods. The female menstrual cycle is a complex pathway, which involves areas of the brain such as the pituitary gland and hypothalamus. Stress affects these areas of the brain, and when this happens, the body’s defense mechanisms focus and turn their attention to processes essential for escaping immediate threat. This can cause periods to be late or missed.

It’s best to try to avoid stress-inducing situations if you can, take regular exercise, try relaxation techniques and get a good night’s sleep to reduce your stress levels and to help maintain a regular menstrual cycle.

If you are experiencing chronic stress or you have missed more than one period, you may want to talk to your doctor.

Weight loss

Significant or sudden weight loss can interfere with your regular menstrual cycle and cause a missed period or even your periods to stop. Severely restricting the number of calories and amount of fat and other nutrients you eat can lower your reproductive hormone levels so that ovulation and menstruation do not occur. This is called amenorrhea.

You should see a doctor or dietician about regaining weight safely if you have missed one or more periods after excessive weight loss. If you have an eating disorder, such as anorexia, you may get support from an eating disorder specialist.

Weight gain

Just as substantial weight loss can cause a missed period, so too can gaining too much weight and becoming overweight can affect your menstrual cycle.

Being overweight can cause an overproduction of the hormone oestrogen that regulates your reproductive system. It follows that too much oestrogen can affect the frequency of your periods and can cause your periods to stop.

If you are overweight and experiencing missed periods you should see your doctor or pharmacist. They can help to advise you on weight loss techniques, including advice, as well as weight loss medication. It could be a sign that you have a medical condition such as polycystic ovary syndrome (PCOS). They can also refer you to a dietician who can advise you about losing weight safely.

Medication

Hormonal medications including some types of birth control and period delay tablets can cause late or missed periods.

Some types of contraception, such as hormonal contraceptive pills, contraceptive injections, and intrauterine system (IUS) particularly the Mirena coil, can cause your periods to stop altogether. However, your periods should return when you stop using these types of contraception.

Period delay tablets such as norethisterone, contain the hormone progesterone. By elevating progesterone levels close to the time of your period, it prevents shedding of the uterus lining which would normally cause a period.

Thyroid problems

Thyroid problems are relatively common. If you have an overactive or underactive thyroid gland it may cause late or missed periods. This butterfly-shaped gland at the base of your neck regulates your body’s metabolism and can produce too many or too few hormones.

If you have a hormonal imbalance that is responsible for your missed or late period, it can easily be detected with a blood test. Often, taking medication can help your periods to return to their normal cycle, once hormonal balance is restored.

Menopause or perimenopause

Menopause is when a woman hasn’t had a period for at least 12 months. The onset of menopause for most women is between the ages of 45 to 55. After menopause, your periods stop completely.

Many women experience symptoms 10 to 15 years before menopause. This menopausal transition is known as perimenopause. During perimenopause, your oestrogen levels begin to fluctuate and this can alter your menstrual cycle. It is common for women in perimenopause to have irregular or missed periods.

Other symptoms of perimenopause include hot flashes, insomnia, mood changes, night sweats and vaginal dryness.

Early perimenopause is when women develop menopause symptoms at age 40 or earlier.

You may start missing periods as you approach menopause. This is because oestrogen levels start to decrease, and ovulation becomes less regular.

Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a very common condition. According to the NHS, it affects about 1 in every 10 women in the UK. PCOS can cause irregular periods or no periods at all.

Polycystic ovaries contain a large number of harmless follicles. These are underdeveloped sacs in which your eggs develop. If you have PCOS, your follicles are often unable to release an egg. This means ovulation does not take place.

Other symptoms of PCOS include excessive hair growth or thinning hair, acne, weight gain and difficulty getting pregnant due to ovulation irregularities or failure. Many women do not have PCOS symptoms. Treatment for PCOS focuses on relieving the symptoms. Doctors may recommend lifestyle modifications such as losing weight and a healthy diet or medication.

Late period and brown or pink discharge?

If your period is late and you have brown or pink discharge, these may be early signs of pregnancy. If you are pregnant, this coloured discharge can be caused by implantation bleeding when the fertilised egg attaches to your uterus lining. Implantation bleeding can happen 1 to 2 weeks after the egg has been fertilised.

You should consider when in your cycle you have had unprotected sex. You're most fertile when you ovulate as this is the time your egg is released from your ovaries. You are most likely to get pregnant around 12 to 14 days before your next period starts. Although possible, it's unlikely that you'll get pregnant just after your period. You should take a pregnancy test if you’ve had unprotected sex, your period is late and you have brown or pink discharge.

Women have some vaginal discharge nearly every day. It’s often clear or white. It can turn pink or brown when it mixes with blood.  This coloured discharge does not necessarily mean you are pregnant. It can also happen for other reasons. Most commonly, it can occur after a vaginal exam, following strenuous sex, or if you're taking birth control pills. It can also be a sign of another medical condition such as PCOS or perimenopause.

Some sexually transmitted infections (STIs) such as gonorrhoea or chlamydia may also cause brown or pink discharge. Other symptoms include painful urination, bleeding, and pain during or after sex, pelvic pain and pressure, vaginal itching, vaginal burning and spotting between periods. Without treatment, STIs can spread to your reproductive organs, causing an infection called pelvic inflammatory disease (PID). You should see your doctor if you have these symptoms who may prescribe antibiotics.

Bad-smelling brown discharge can indicate that a foreign object, such as a tampon, condom or contraceptive is left in your vagina accidentally and you should see your doctor.

How about if my period is late and I have spotting instead?

Spotting is light bleeding during your menstrual cycle, but not enough to be considered a period. If you have spotting instead of your usual period, it is advisable to take a pregnancy test. Spotting is a sign of early pregnancy, especially if it is accompanied by other pregnancy symptoms such as nausea with or without vomiting, tiredness and fatigue, dizziness, breast changes such as tenderness and frequent urination.

Spotting can occur 1 to 2 weeks after fertilisation when the fertilised egg implants in the lining of your uterus. It is not uncommon to have spotting after sex or after a vaginal exam.

However, several health issues can also cause spotting. It can also be a sign of infection such as STIs and PID, stress, or other medical conditions such as PCOS or thyroid conditions. It doesn’t always spell pregnancy.

So, how late can my period be before I should worry?

If your period is late and you have recently had unprotected sex, it can be an early sign of pregnancy. Whilst that is a fact, it’s not always the case. Only a pregnancy test will give you the answer. How late your period is, depends on your cycle. Only you know what is normal for you, and what isn’t.

Home pregnancy tests are available from pharmacies and some supermarkets. Results tend to be accurate if you follow the instructions correctly. If you take the test too early, the results may not be reliable. The best time to take a pregnancy test is the week after your missed period. Your body takes a week or so to develop levels of HCG (the hormone produced by the placenta during early pregnancy), which is what the test relies on.  

A positive test result is almost certainly correct, with most tests claiming 99% accuracy. By the same token, a negative result is also likely to be correct.  Only 5% of pregnancy tests give a false negative result. If you test negative and you still think that you're pregnant, you should wait a few days and try again. If you have a negative test result and you are experiencing other early pregnancy symptoms, speak to your doctor or pharmacist.

If you have a positive pregnancy test, you should see your doctor to confirm your pregnancy. If your pregnancy test results are positive but you are worried or experiencing any warning signs that something is wrong with your pregnancy, such as bleeding or cramping, you should call your doctor right away.

However, there are reasons other than pregnancy, why your period can be late. Common causes can range from perimenopause and hormonal imbalances to medical conditions such as thyroid, PCOS or diabetes. You should see your GP if you're not pregnant, you've had a negative pregnancy test and you've missed more than 3 periods in a row. Your doctor can properly diagnose the reason for your late period and discuss any treatment options.

Late periods – the verdict

Try not to fret if your period is late. Stress can affect your hormones and your menstruation. There are a bunch of reasons why your period may be late including pregnancy, irregular periods, weight changes, infections, medical conditions such as PCOS and hormone changes when hitting perimenopause.

If you're sexually active, your period is later than normal and you have not taken a pregnancy test, it may be advisable to take one.

Whilst all of our content is written and reviewed by healthcare professionals, it is not intended to be substituted for or used as medical advice. If you have any questions or concerns about your health, please speak to your doctor.