Six reasons for a missed period (apart from pregnancy)

A late or missed period can be concerning, but it’s usually nothing to worry about. Your menstrual cycle can be influenced by factors such as stress and changing exercise habits.

However, if you’ve had unprotected sex, it could also be a sign of pregnancy. To help us understand more, practicing GP, Dr Neel Patel from LloydsPharmacy Online Doctor, offers his expertise on what to do if your period is late or doesn’t come at all – and explains six common causes.

How do you know if your period is late?

Most periods occur approximately every 28 days, however a normal cycle can be anywhere from 21 to 40 days. It’s also common to have an irregular menstrual cycle which means your period might appear at different times during the month.

If your period usually follows the same cycle (such as every 28 days) then it is considered late if it doesn’t occur after one day. However, this is not an immediate cause for concern.

Is it normal to miss a period? 

Missing a period can be alarming but it’s actually very common and doesn’t necessarily mean you are pregnant. Various factors can affect your menstrual cycle such as stress, weight changes and the contraceptive method that you use.

Six common reasons you might miss a period

So why might you miss your period? Here are six common reasons – aside from pregnancy.

1) Exercise

Too much exercise can place stress on the body which in turn, can affect the hormones responsible for your periods. If your periods become irregular, or stop completely, you may wish to reduce your level of physical activity. Athletes should speak to a specialist doctor who can advise on how to manage exercise and their periods.

2) Stress

Stress impacts the body in many ways, one of which is the menstrual cycle. If you’re stressed, your periods may become heavier, more painful, longer or shorter. Or they may stop altogether. 

Avoiding stress by practicing self-care or having talking therapies such as CBT can help you to manage these symptoms.

3) Weight

You may find that your periods stop if you suddenly lose weight. This is because restricting calories can stop the production of hormones that are needed for ovulation. 

Alternatively, being overweight can also impact your menstrual cycle, causing the body to overproduce oestrogen which affects how often periods occur. If you are over or underweight, your GP may refer you to a dietitian who will help you to reach a healthy weight.

4) The contraceptive pill 

Some methods of contraception, such as the coil and injection, can result in a missed period. This is normal and is not usually something to be worried about. The contraceptive pill can also make periods irregular and be used to delay your period if you wish to skip a cycle.

Taking packets of the pill back-to-back is perfectly safe and useful for when you want to avoid a bleed such as on your holiday. Period delay medication will also delay your period and can be taken if you’re not already on the combined pill.


As many as 1 in 3 people with PCOS (polycystic ovary syndrome) experience stopped periods as a result of the condition. This is due to underdeveloped sacs in which the eggs normally grow, causing the body not to ovulate and instead, skip a period.

6) Menopause

Menopause typically occurs between the ages of 45 and 55. During this time, your periods will become irregular and eventually stop as a result of hormone levels lowering. This can also happen earlier, otherwise known as premature menopause.

What if there is a chance you could be pregnant?

If you are sexually active and you’ve missed a period, there is a chance you might be pregnant. This can happen even if you have used contraception. It is also possible to get pregnant whilst on your period if ovulation has been delayed.

When should you take a pregnancy test? 

For the most reliable results, take a pregnancy test any time after the first day of your missed period to determine whether or not you are pregnant. You can do this at any time of day. If the test is negative and you think you may be pregnant, wait a few days and take another test.

It can be helpful to know the early signs of pregnancy. Aside from a missed period, these include:

  • Tender breasts
  • Nausea and vomiting
  • Tiredness
  • Constipation
  • Urinating more often
  • Changes to sense of smell and taste

Having one of these symptoms doesn’t necessarily mean you are pregnant, it could be a result of stress, or a late period.

What should you do if your pregnancy test is negative?

If you have taken a pregnancy test and had a negative result, then it might be worth visiting your GP to discuss other possible causes for a missed period.

One missed period is normally nothing to worry about, but if your period becomes unpredictable, or you miss three periods in a row, you should seek medical advice.

Photo by Sasun Bughdaryan