My period hasn’t come, but my pregnancy test shows one line

If you tested before your period was due, test again a few days later. If the result is negative again and your period still hasn’t come, or if you have pain or bleeding, see a doctor. This is also why we ask about your test dates and results at a visit: once you match up whether you read the result window correctly and where that day fell in your cycle, the next step becomes clear.

Your expected period date has passed, but your period hasn’t come, and the test shows only one line. You may find yourself alternating between “If I’m not pregnant, why hasn’t my period started?” and “Did I test too early?”

It helps to look back at when and how you tested, rather than how many tests you have used. Let’s work through what you need to know to interpret today’s result.

Does one line mean I’m not pregnant?

First check whether the result matches the instructions for a negative result, and whether the test worked properly. Tests that show results with lines have a control line to indicate that the test is working. If the control line does not appear, do not interpret it as negative. Follow the instructions and use a new test.

The expiry date and the time for reading the result also matter. Check the result within the time specified by the product, rather than taking out an old test long afterward to interpret it again. The display and instructions differ between products.

Even a negative result from a correctly used test may not completely rule out pregnancy if you test too early. A urine pregnancy test detects a hormone called hCG, which is associated with pregnancy. In early pregnancy, there may not yet be enough of this hormone for the test to detect.

Is it really one line? Faint lines and tests that show no result

Before deciding on a result, tell apart the spot where the control line forms and the spot where the test line forms in the result window. The control line is a sign that the test has worked, and the test line appears when a pregnancy hormone has been detected in your urine. The letters or symbols marking these spots differ between products, so keeping the picture in the instructions from the box beside your test makes it less confusing.

• If only the control line appears: This is the pattern the instructions classify as negative. Whether you can accept that reading as it is gets decided together with the testing date covered in the next section.
• If the test line is very faint: A line that forms within the time allowed by the instructions is not treated as absent, even if its color is pale. You can test again on another day or have it checked at a clinic.
• If there is no control line at all: The test itself did not work, so it is not used for a reading. This applies even if another line is visible, so start again from the beginning with a newly opened test.

A faint second line: reading time and evaporation lines

When interpreting a faint line, when it appeared matters more than how dark it is. A line that appears within the reading window specified in the instructions counts as part of the result even if it is faint; a line that appears well after that window does not. Reading windows vary by product. Note the time when you apply urine and check the result at the instructed time.

If left for a long time, the result window may dry and leave a thin, almost colorless mark, commonly called an evaporation line. This is not a reaction to pregnancy hormone and is not treated as a positive result. Looking again at a test hours later or the next day is not a valid way to interpret it.

Conversely, do not dismiss a faint line that appeared within the reading window just because it is pale. Very early in pregnancy, low hormone levels may produce a faint line that becomes clearer a few days later. If you are unsure whether it appeared within the window, repeat the test a few days later with the first urine of the morning, or seek medical confirmation through a blood test or another appropriate test.

If you also notice light bleeding around the time of a faint line and are unsure whether it is your period, see Implantation bleeding or a period: how to check for the timing of bleeding and the steps for checking.

Could you have tested too early? Early tests and standard tests

Even with a sensitive product such as an early test, you can see one line during pregnancy if you test far too soon. The hCG a test looks for is made by the body only after a fertilized egg implants, and passes into the urine; in early pregnancy its amount grows as the days go by. So the same person can see a different result within a few days.

The difference between the two lies in the amount of hCG they react to. Early tests are made to react to small amounts, and many say they can be used before your period is due; standard tests are usually meant for use after your period is due. When we ask about dates at a visit as well, if your cycle is regular, counting based on your expected period date rather than the day you had sex is less confusing.

Around your expected period date, many products say to use the concentrated urine you pass when you first get up. One line seen before your period is due may be a record made ‘before the answer is ready’. Leaving a gap of some days and checking once more tells you more than using several tests in a row on the same day.

When should I test again?

Choose the timing according to whether you know when your period is due. If the result is negative but you still think pregnancy is possible, test again a few days later.

Some products can be used before your period is due, but an early negative result does not replace a later test. If you have had sex that could result in pregnancy since your last test, the previous result cannot tell you whether you became pregnant afterward.

Drinking excessive amounts of water just before testing to make yourself urinate can dilute your urine and affect the result. Follow your product’s instructions on the time of testing and how to apply the urine.

What if the next test is negative and my period still hasn’t come?

If a second test is negative and your period still hasn’t started, consult a gynecologist. It is better to review the dates and symptoms together than to keep testing on your own.

Besides pregnancy, factors such as stress, a major weight change, strenuous exercise and hormonal contraception can affect when your period comes. Still, avoid deciding in advance that “I’ve been tired lately, so that must be why.” A test result alone cannot explain why your period is late.

Before your visit, make a brief note of the following. If you cannot remember something exactly, it is fine to share what you do know.

• The first day of your last period and your usual interval between periods
• Dates of sex that could result in pregnancy and the contraception used
• Dates and results of pregnancy tests
• New pain or bleeding, medicines you take and recent lifestyle changes

During the consultation, this information helps your clinician decide whether a repeat test, blood test or other assessment is needed. Different tests have different limits, so not everyone has the same tests. To see what is checked at the clinic and in what order, read How are changes in your menstrual cycle evaluated, step by step?. For care when your period has been absent for months or your cycle stays irregular, see Irregular Periods / Amenorrhea.

Why your period can be late when you’re not pregnant

If you are not pregnant, the next step is to look for other changes that may have delayed or stopped ovulation. The cause is not always a single factor, and several can overlap, so your lifestyle and health over the past few months are considered together.

• Stress and daily rhythm: When your body’s rhythm is disrupted by major worries, too little sleep or shift work, ovulation can be delayed and your period can come later.
• Weight changes and exercise: Your cycle can also change after a large weight loss or gain over a short time, or a sudden increase in exercise.
• Polycystic ovary syndrome: If irregular ovulation keeps making the gap between periods longer, you can be checked for Polycystic Ovary Syndrome.
• Thyroid function: Both too much and too little thyroid hormone can change your cycle, so if you also have tiredness or weight changes, a blood test is sometimes used to check it.
• Medicines you take: The timing of your period can change right after stopping or switching hormonal birth control pills, or while taking certain medicines. If you want to reconsider your contraception, see Contraception.

If you are planning a pregnancy, it can help to find out early why your cycle is irregular. You can discuss this during a Preconception Checkup.

Are there times when I shouldn’t wait for the next test?

If pregnancy is possible and you develop lower abdominal pain or bleeding, seek medical care promptly. This applies even if you have not had a positive result. In particular, tell your clinician if the pain is on one side of your lower abdomen.

These symptoms alone do not establish a cause, but some situations need prompt assessment, such as an ectopic pregnancy, in which a pregnancy develops outside the uterus. It is important not to put off care based only on the number of lines on a test. If you have already confirmed a pregnancy and then develop bleeding or pain, also see Early Pregnancy / Threatened Miscarriage.

Questions before testing or a visit

Can I test with urine from the evening?

The test itself works in the evening. Just keep in mind that if the water you drank during the day has diluted your urine, the test line may come out weak or not show. If it is still early, such as around your expected period date, test once more the next day with the urine you pass when you first get up.

The second line looks very faint.

If a faint line formed within the time set in the instructions, do not settle on a negative result. Test again on another day with the urine you pass when you first get up, and if it is still unclear or you want an answer sooner, the tests that are needed can be chosen and done at a clinic.

I took birth control pills or emergency contraception, and my period is late.

Home pregnancy tests check for a hormone called hCG in urine. Medicines containing hCG, such as injections used in fertility treatment, can therefore affect the result. This article alone cannot determine how birth control pills or emergency contraception may have affected your test result or the timing of your period, so tell your clinician which medicines you took and when. If you are concerned about any medicine you are currently taking, check with a healthcare professional.

My tests keep coming back negative and my period still hasn’t come. When should I see a doctor?

Go by timing rather than the number of tests. If a repeat test after your expected period date is also negative and your period still hasn’t come, that is the point to move on to a visit. It is a stage for looking for the cause together rather than using more tests, and if pain or bleeding comes with it, seek care right away regardless of the date.

I’m bleeding a little, but the test shows one line.

If pregnancy is still possible, do not conclude that this bleeding is your period just because the test shows one line. If bleeding continues or differs from your usual period, seek medical care rather than relying only on an information page. If you have pain on one side of your lower abdomen, feel dizzy or feel as though you might faint, conditions such as an ectopic pregnancy need to be ruled out: do not wait; seek medical care immediately or go to an emergency department. For other causes of bleeding, you can also refer to Abnormal Vaginal Bleeding.