Pregnancy tests
You are more likely to get an accurate result if you wait until the day of your missed period or any time after that.
My negative test turned positive: am I pregnant?
You’ve taken your pregnancy test, and it was negative. But when you go back to it later or see it when you clear out the bin, there’s a line! What gives?
Whether the Two Week Wait is finally over, you’re doing a pregnancy test a bit early because you just can’t wait or you’re late for your period and just double-checking, using a pregnancy test can be a nervy experience.
So what does it mean if your negative result somehow has turned into a positive one later on? Unfortunately, one way or another, it’s a sign that something has gone wrong with the test. Read on to find out more about why this might happen.
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That’s why the instructions on pregnancy tests tell you to look at the results within a certain time frame. If you look too late, you can end up with evaporation lines, which can trick you into thinking you have a positive result.
What it comes down to is: if your test said that you were not pregnant during the time window for taking a reading, then it is still negative EVEN IF you see a line after that time.
What a false negative on a pregnancy test?
That said, you can get what’s called a ‘false negative’ on pregnancy tests. A false negative occurs when it’s just too early to tell if you’re pregnant. Pregnancy tests measure the levels of pregnancy hormone hCG (human chorionic gonadotropin) in your urine and if the hCG hasn’t built up enough to register on a test, the your test will be negative.
If you want to be sure, wait a few days and test again.
Photo credit : Netmums user Dede80
Why did my pregnancy test change from negative to positive?
There could be several reasons why your pregnancy test results go from negative to positive.
- It’s most likely because you’re reading the test after the recommended time. Most pregnancy tests will tell you to take your reading between 2 and 10 minutes after you pee on the stick, and if you read it after that the results are invalid.
That’s because after a while the urine on the test will evaporate, leaving what’s called an evaporation line. Unlike a positive result which will have a small amount of the red or blue dye the test uses to show them, evaporation lines are faint and colourless. They can quite easily be mistaken for a faint positive line, which could lead you to think that your result has changed from negative to positive. - Another reason why you could end up with an evaporation line is if you accidentally splashed a bit of wee onto the results window when you were first using the stick.
Either way, if you checked your test within the time that the instructions said to and it was negative, then you are probably not currently pregnant.
If you think it could just be too early to test, depending on when you last ovulated and when conception occurred, wait a few days or a week then test again.
Take a look at : 14 ways to increase your chances of getting pregnant
Trying to get pregnant and want to make your chances as high as possible? Find out some of the easy steps you can take to increase your chances of getting pregnant – from fertility tracking, to your health, to what your partner can do.
If you would like more information about pregnancy tests and how they work, take a look at the stories below. You can also head over to our Forum to talk to other parents and hopeful parents for support and answers.
Pregnancy tests
If you think there is a chance you are pregnant, you may wonder when you can take a pregnancy test.
You are more likely to get an accurate result if you wait until the day of your missed period or any time after that.
There are some very sensitive pregnancy tests that you can do as early as 8 to 10 days after conception (the day you got pregnant).
You can take a pregnancy test at home. Your GP or GP practice nurse will also be able to do a pregnancy test for you.
Visit your GP
If you think you might be pregnant, it is a good idea to visit your GP as soon as possible. They can confirm your pregnancy and talk to you about your feelings.
Confirming your pregnancy with your GP
Home pregnancy tests
You can buy home pregnancy tests over the counter in your pharmacy. They are also sold in many shops and supermarkets.
Read the instructions on the pregnancy testing kit before using it. The instructions will tell you what the different colours or symbols mean.
How pregnancy tests work
Pregnancy tests detect the levels of a hormone called hCG in your urine (pee). This hormone is produced during pregnancy. It is present in your bloodstream and your urine.
In early pregnancy, the amount of the hormone in your system increases. The later you leave it to take a pregnancy test, the higher the hCG levels will be.
The earlier you take the test, the more likely you are to get a ‘false negative’ result. This is where the test shows up as negative even though you are pregnant.
Sometimes you can get a ‘false positive’ from your test. This is when you leave it too long and an ‘evaporation’ line appears. Sometimes this is mistakenly read as being pregnant.
Pregnancy tests your GP may do
Your GP will probably do a urine pregnancy test to check if you are pregnant.
It may help to bring a sample of urine with you if you think you may be pregnant. This means you will not have to pee under pressure there.
The pregnancy testing kit your doctor uses will look like the kit you buy over the counter.
Your GP may do a blood test to check the level of hCG in your blood.
They may do this if you:
- had vaginal bleeding
- have severe tummy pains
- have severe morning sickness
Accuracy of pregnancy tests
A positive pregnancy test is almost always correct. Some negative tests may not be correct. A ‘false negative’ means your test is showing negative, but you are pregnant.
This may happen because:
- you did the test too early
- you did not wait long enough before checking the result (always follow the instructions – results often take 3 minutes to appear)
- your urine is very diluted because you drank a lot of water
- there is a fault with the test
If the result of the test is negative, and you still think you might be pregnant, repeat the test a few days later. If you are still unsure after a few negative tests, contact your GP.
If the result is positive
If your test is positive, you should visit your GP to confirm the pregnancy and sign up for antenatal care.
If you are not sure you want to be pregnant, it may help to discuss your options with your GP.
Sometimes counselling can help you work through your feelings about being pregnant. It may help you decide what’s right for you.
