Pregnancy or a late period? Other reasons your period might be late

Pregnancy is the first thing most of us think of when a period is late. But it’s far from the only reason, and the NHS says that most of the time it’s nothing to worry about, though it’s still worth seeing a GP to check.

Start with a test

If you’ve had sex since your last period, take a pregnancy test. Testing from the day your period is due is more reliable than testing early, but a negative can still be wrong if there isn’t enough hCG yet. If it’s negative and your period still doesn’t come, test again a few days later. See can a negative test be wrong?

If your cycles are irregular and you don’t know when your period is due, test at least 21 days after you last had unprotected sex.

Other reasons for a late or missed period

Stress

Stress can delay or stop a period. If stress is affecting you, a GP can offer advice or therapy.

Weight changes

Sudden weight loss, losing or gaining a lot of weight, or being overweight can all affect your periods. A GP can give you advice about reaching a healthy weight.

Exercise

Doing too much exercise can make periods late or stop them.

Hormonal contraception

Some methods, like the pill, the injection and the hormonal coil (IUS), can make your periods lighter or irregular, or stop them. After you stop hormonal contraception, you may have a withdrawal bleed within a few days or weeks, which is lighter than a period. After the injection, your periods and fertility often take longer to come back, but you can still get pregnant before your first period.

Breastfeeding

Breastfeeding can stop or delay your periods.

Polyendocrine metabolic ovarian syndrome (PMOS)

Polyendocrine metabolic ovarian syndrome (PMOS), which used to be called polycystic ovary syndrome (PCOS), can cause irregular periods or long gaps between them. Other symptoms include excess hair growth or hair loss, weight gain or difficulty losing weight, oily skin and acne, and feeling very tired. It can make it harder to get pregnant, usually because the ovaries don’t release an egg each month.

Perimenopause

The start of the menopause, called perimenopause, usually between the ages of 45 and 55. See pregnancy or perimenopause?

Other medical conditions

Periods can sometimes stop because of a medical condition, such as an overactive or underactive thyroid, diabetes or heart disease.

Normal variation

Sometimes the gap between periods just varies. See when is a period late?

When to see a GP

you’ve missed 3 periods in a row
you’ve had two negative tests, your period still hasn’t come, and you think you could be pregnant
you’ve missed a period and have other symptoms, like weight gain or loss, tiredness, hair growth on your face, or dry or oily skin
your periods have become irregular
your periods are irregular and you’re struggling to get pregnant

Getting ready for a GP appointment

The GP will ask about your health, so it helps to have a few things ready:

the dates your last few periods started, and how long they lasted
the dates and results of any pregnancy tests
any other symptoms, such as weight gain or loss, tiredness, extra hair growth, or changes to your skin
any contraception you use or have recently stopped, and any other medicines
whether you’re trying to get pregnant

What the GP may do

A GP will ask about your health and may arrange blood tests to find the cause. They may refer you to a specialist, such as a gynaecologist or an endocrinologist (hormone specialist), if you need more tests or scans.

Treatment depends on the cause. For example, the combined pill can help with PMOS, and HRT with perimenopause symptoms. If you’re trying to get pregnant, tell your GP, as it affects which treatments suit you.

When it’s urgent

Contact your GP or call NHS 111 straight away if you might be pregnant and have a combination of these: tummy pain low down on one side, vaginal bleeding or a brown watery discharge, pain in the tip of your shoulder, or discomfort when peeing or pooing. Do this even if you haven’t had a positive test. These can be signs of an ectopic pregnancy, which affects around 1 in 90 pregnancies.

Questions people ask

Can stress make your period late?

Yes. Stress is one of the common reasons for a late or missed period. If it’s affecting you, a GP can offer advice or therapy.

Can you be pregnant with a late period and a negative test?

Yes, if you tested before there was enough hCG to find. Test again a few days later, and speak to your GP if you’ve had two negative tests and your period still hasn’t come. See false negative pregnancy tests.

Can PMOS (PCOS) cause a late period?

Yes. Irregular periods or long gaps between periods are one of the main symptoms of PMOS, which used to be called PCOS.

Can coming off contraception make my period late?

After you stop hormonal contraception, you may have a withdrawal bleed, which is lighter than a period. After the injection, your periods and fertility often take longer to come back. You can still get pregnant before your first period, so take a test if you’ve had unprotected sex.

When to get help

Mild cramps that ease with rest are usually nothing to worry about. But if you’re pregnant, or think you could be, get urgent advice from your maternity unit, an early pregnancy unit or NHS 111 if you have:

any bleeding or spotting, even if it’s light
tummy pain that’s severe, on one side, or hasn’t eased after resting for 30 to 60 minutes
pain in the tip of your shoulder

Call 999 if you have bleeding along with severe tummy pain, pain in your shoulder, or feeling sick, faint or dizzy, or if the bleeding is heavy (soaking a pad soon after putting it on). Also call 999 if you have sudden, sharp and intense tummy pain and you feel very dizzy or faint, feel sick or look very pale. These can be signs of an ectopic pregnancy or a miscarriage that need treating straight away.