So, you’re looking at the test line on the pregnancy test and wondering why the second “You’re pregnant!” line isn’t popping up. Your period’s late, your boobs are tender, and you’re nauseous, but the test is still showing up negative. Can you get a false negative pregnancy test? Can you be pregnant and have a negative pregnancy test?
Yep, it is possible to get a negative pregnancy test result when you are really pregnant. And if you think you’re in that situation, it’s important to get your pregnancy confirmed ASAP so you can get all your pre-natal care set up, ready to get on with the business of growing your baby.
So how can a false negative pregnancy test result come about, and what should you do if you get one? We’ve got you.
Table of Contents 📝
- How does a home pregnancy test work?
- What can cause a false negative pregnancy test?
- What are the chances of a false negative pregnancy test?
How does a home pregnancy test work?
A home pregnancy test works by detecting a hormone called hCG (human Chorionic Gonadotrophin) in your urine. After conception, your little baby-to-be (or embryo) implants in the lining of your uterus and the placenta – your baby’s amazing life-support system – starts to grow. It’s the placenta that sends out the hCG, saying: I’m getting to work now!
Once you’ve peed on the pregnancy test stick, the chemicals in the test should react with the hCG – if present – leading to a positive or negative result within a few minutes.
Sounds simple. So what can go wrong? Why am I having pregnancy symptoms but a negative test?!
What can cause a false negative pregnancy test?
Let’s look at a few potential solutions to the mystery of the false negative pregnancy test:
Taking the test too early
Of course you’re impatient to know whether you’re pregnant or not – we get it! But taking a pregnancy test too early increases your chances of a negative pregnancy test result, because there might not be enough hCG for the test to detect yet.
To give the test the best chance, leave it until a few days after you expected your next period to start. Or at least until the day itself (if you just can’t wait!).
Making a mistake when taking the test
In your excitement to take the test, you might be tempted to skip over the instructions on the pack – but don’t do it! You might make a mistake that could affect the accuracy of the result, like:
- Checking the test results too soon (or too late). Make sure you give the test enough time to work properly (usually 2 to 3 minutes) but don’t leave it too long before looking either. That can actually lead to a false positive pregnancy test result.
- Testing with urine that’s too diluted. The test has the highest chance of detecting hCG first thing in the morning when your urine is most concentrated. But if you do test later on, just try to avoid drinking loads of liquid beforehand.
A test that’s past its best
Check the expiry date on the test packaging, as a test that’s out of date may not work properly.
The hook effect
In rare cases, you may get a false negative pregnancy test result when you have a really high amount of hCG in your body. This is known as the “hook effect”.
Seems counterintuitive we know, but it’s sort of like when you’re faced by a vast selection of candy bars. You may get choice-overload and run out of the store without buying anything. And something similar happens with the test: there’s so much hCG that it refuses to flag up that there’s anything there at all.
The hook effect can be the result of:
- Being too far along in your pregnancy (your last period is a distant memory)
- Being pregnant with twins or triplets
- Some fertility medications
- A molar pregnancy
It’s rare, but sometimes an ectopic pregnancy (where the embryo implants somewhere other than the uterus) is not detected by a pregnancy test. If you’ve missed your period and have severe abdominal pain, make sure you get in touch with your doc straight away.
What are the chances of a false negative pregnancy test?
How common is a false negative pregnancy test? A “true” false negative pregnancy test result (where the test has genuinely malfunctioned) doesn’t happen all that often.
But it’s quite easy to take the test too early or at the wrong time of day and voila! A confusing test result.
The best thing to do? Double-check those instructions, repeat the test a few days after your missed period was due to start, and – if in doubt – head over to your doctor’s office. They’ll be able to do further tests to confirm whether or not you’re really pregnant.
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