Couple getting pregnancy test result

All About Pregnancy Tests

June 14, 2019
4 min read

Have you missed a period or noticed any other signs of pregnancy? Then you may be wondering when to take a pregnancy test, how they work, the types available, how accurate they are, and what to do if you get a positive result. Read on to find out!

What's in this article:

How Do Pregnancy Tests Work? What Types of Pregnancy Tests Are There? Where Can I Get a Pregnancy Test? How to Use a Home Pregnancy Test? When Can I Take a Pregnancy Test? How Accurate Is a Home Pregnancy Test? What Should I Do If the Pregnancy Test Is Positive? FAQs at a Glance

How Do Pregnancy Tests Work?

Pregnancy tests work by detecting a pregnancy hormone called hCG, human chorionic gonadotropin, in either your urine or blood. This hormone is produced from about six days after conception. During early pregnancy hCG levels double every two days, so hCG becomes easier to detect as the days progress. This is why it’s a good idea to wait until after the first day of your missed period to take the test, as taking the test any earlier may result in a false negative.

What Types of Pregnancy Tests Are There?

The presence of hCG can be detected with:

  • A urine test. Home pregnancy tests work by detecting hCG in your urine. You’ll find a range of brands available on the market including some digital pregnancy tests. Some brands are more sensitive than others – meaning they may even work four or five days before your period is due. These tests allow you to check for pregnancy in the privacy of your own home at a time that suits you. If you’d like help taking the test, you can ask your GP or the staff at your local sexual health clinic.
  • A pregnancy blood test. This type of test must be done at the doctor’s office, and results may only come back in a few days. Pregnancy blood tests are more sensitive than urine tests and can detect the amount of hCG in your blood – not just whether the hormone is present at all. They can also detect hCG a little earlier – even six to eight days after ovulation. Experts usually recommend taking a home pregnancy test instead of going for the blood test but check with your GP if you’re unsure about what’s right for your situation.

Where Can I Get a Pregnancy Test?

You can buy a home pregnancy test at many pharmacies and supermarkets. However, you may also be able to get a free test from your GP, at community sexual health clinics, at some youth service centres, and Brook centres if you’re 25 or under. All of these services are confidential. Find your nearest pregnancy testing service here.

How to Use a Home Pregnancy Test?

Home pregnancy tests are pretty easy to use but you must make sure to carefully follow the instructions inside or on the pack. Each brand is a little different, for example, you may have to wait until at least the first day of your missed period for some tests to be accurate.

The tests typically work any time of day, but levels of hCG are more concentrated in the first urination of the day so some brands may recommend doing the test first thing in the morning.

Tests also vary in how they are taken. For example, you may need to pee on a test stick by holding it under your urine stream for a few seconds, while other tests require you to pee into a cup and then place the stick into the urine for a time.

The results usually appear within a few minutes but keep in mind the wait times can be a little different among brands so follow the instructions. Don’t check the result too early otherwise you may not get an accurate reading, and in some cases you shouldn’t read the result after about 10 minutes as it may no longer show the accurate result. You may even want to set a timer, so you check the test results within the brand’s recommended window.

The instructions will also tell you how your product will show its results. For example, some tests show a positive result by displaying two lines – not just one. In this case even two faint lines on a pregnancy test may still indicate you are pregnant. Other brands show their results in other ways. If you’re in any doubt about your result take the test again in a few days or ask your GP for help.

When Can I Take a Pregnancy Test?

The most accurate time to take a home pregnancy test is from the first day of your missed period onward. In fact, you may not even suspect you are pregnant any earlier because missing your period is likely the earliest and most reliable clue that you are pregnant. Other early signs of pregnancy that you may notice include

  • tender or swollen breasts
  • needing to pee more often
  • feeling nauseous
  • feeling tired.

How Accurate Is a Home Pregnancy Test?

A positive result on a pregnancy test is almost certainly accurate as long as you have followed the instructions on the pack carefully. However, false-positives can happen in rare circumstances, for example, if a test picks up on hCG that’s been part of your fertility treatment.

A negative result may be less reliable. If have received a negative result but still think you may be pregnant, wait a few days and take another test or ask your GP for a pregnancy blood test. These factors may lead to an inaccurate result:

  • Taking the pregnancy test too early. If you take the test before the first day of your missed period levels of hCG may still be too low for the test to detect.
  • Not following the instructions. Check when and how the pregnancy test should be taken and follow these instructions carefully. For example, wait the correct amount of time to read the result.
  • Drinking too much fluid beforehand. This can dilute the amount of hCG in your urine so the test may not be able to detect its presence. It may help to take the test first thing in the morning when levels of hCG are most concentrated in the urine.
  • Taking certain medications. Most medications won’t affect a home pregnancy test, but some medications used to treat infertility, and some anticonvulsants, diuretics, sleeping tablets, and others may affect the accuracy of the results. Ask your GP or the pharmacist, or read the instruction leaflet to check for any medicines you’re taking.

What Should I Do If the Pregnancy Test Is Positive?

Once you learn the good news, make an appointment with your GP or midwife so that your antenatal care can start. Congratulations! We’re really excited for you.

If you want to know how far along you are, check out our Due Date Calculator to get an approximate idea. You might also want to take a look at our go-to pregnancy guide for interesting and exciting information about what’s to come, and you can also sign up for our emails for great tips and articles delivered straight to your inbox.

FAQs at a Glance

When can I take a pregnancy test?

Pregnancy tests are most reliable from the first day of your missed period onward. Some tests may work as early as four or five days before your period is due but the instructions included with your test will tell you when that specific brand works best.

How accurate are pregnancy tests?

A positive result is almost always accurate, but a negative result is less reliable. If you have received a negative result but still think you may be pregnant take another test in a few days or ask your GP to confirm it.

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