My period is late but my pregnancy test is negative. Why?

A negative pregnancy test does not always rule pregnancy out, and a late period with a negative test is common enough that the NHS gives a plain next step: wait a few days and test again. The NHS says a negative result is less reliable than a positive one, especially if you tested too early or did not follow the instructions. This page cannot tell you why your period is late, so it sticks to what the sources say about testing, what else can delay a period, and when to call a doctor.

What the sources say about the test

• Timing matters. The NHS says pregnancy tests are most reliable from the first day of your missed period. If you do not know when your period is due, it advises testing at least 21 days after unprotected sex.
• A negative is less certain than a positive. The NHS says a negative result is less reliable, and that a positive one is almost certainly correct. Testing too early, not following the instructions, and some medicines can all affect the result.
• Test again. If you get a negative result but still think you might be pregnant, the NHS says to wait a few days and test again.
• If it is still negative and still no period. The NHS says to speak to your GP if you get a negative result after a second test but your period has not arrived.

What else can delay a period

If you are not pregnant, the NHS lists stress, the start of menopause (usually between 45 and 55), PMOS (which used to be called PCOS), sudden weight loss or being overweight, doing too much exercise, breastfeeding, and certain hormonal contraception such as the pill, injection or IUS. It adds that conditions such as diabetes or an overactive or underactive thyroid can also stop periods. MedlinePlus names pregnancy as the most common cause of missed periods, and also lists low body fat and severe anxiety or emotional distress. The NHS says most of the time a missed or late period is nothing to worry about, but it is worth seeing a doctor just in case. The longer list is on why your period might be late. If you recently stopped hormonal contraception, see a period that is late after stopping the pill. If your cycle is often unpredictable, see why your periods might be irregular.

What is worth writing down

The useful details for a doctor are the first day of your last period, the date and result of each test, the brand if you remember it, and anything else that has changed, such as weight, tiredness, skin, hair, stress or breastfeeding. A period tracker built for Muslim women keeps your cycle dates and the days you tested in one place, and Nisaa is free on the App Store.

If you are a Muslim woman wondering about prayer and fasting

This page does not issue a ruling. If bleeding then starts, what counts as hayd and how the schools set its limits is covered in what counts as hayd, and light bleeding that may be something else is covered in implantation bleeding or your period.

When to speak to a doctor

• The NHS says to see a GP if you have missed your period 3 times in a row, if your periods have become irregular, or if you have missed a period along with other symptoms such as weight gain or loss, tiredness, or dry or oily skin.
• The NHS says to speak to your GP if a second test is negative and your period has still not arrived.
• MedlinePlus says to see a health care provider if you have missed more than one period, so that the cause can be found and treated if needed.

If the pregnancy ended in a miscarriage, see when your period comes back after a miscarriage.

If you are wondering how the timing of sex fits with a late period, see can you get pregnant on your period.