Yes, wrong pregnancy test results can and do happen. In fact false negatives – where the pregnancy test says you’re not pregnant but you actually are – are more common than false positives.
However, it’s also important to say that this shouldn’t give you false hope. A negative pregnancy test is still most likely to mean you’re not pregnant.
But if you really believe you are pregnant and have pregnancy symptoms (here are 41 early pregnancy signs in case you’re not sure), there’s a chance you may be right.
Read more: 6 reasons you might get a false positive
“If you think you may be pregnant but the pregnancy test is negative, there may be several reasons,” says our expert midwife Nikki Khan.
Reasons for a false negative pregnancy test result
1. You took a pregnancy test too early
“Home pregnancy tests measure a specific hormone in the urine called human chorionic gonadotrophin (hCG), which is only present when a woman is pregnant,” Nikki explains. “It’s produced from the very early stages of pregnancy following egg fertilisation.
“Some pregnancy tests are more sensitive than others to this hormone and claim to be able to detect several days before you miss your period.
“But they don’t always detect hCG levels this early in pregnancy, especially if your levels are very low. For this reason, most brands suggest repeating the test in a few days.”
The opportunity to test for pregnancy earlier due to the increased sensitivity of today’s tests, also increases the risk of testing before your hCG levels are high enough to detect.
One mum, Snappyloz, in our forum, explained how she got wrong pregnancy results. “I have had false negatives but only when I’ve tested before my AF [Aunty Flow – eg my period] was due. The ones taken after have always been accurate. However it does all depend on when you’ve ovulated.”
Wifey2479 had a similar experience: “I had 3 false negative results, then 2 days later brought a Clearblue digital one and sure enough I was pregnant. I think I just tested too early.”
2. You tested at the wrong time of day
On our forum, we’ve noticed a fair bit of chat about what time of day to take a pregnancy test to get the optimum results. “It’s best to test with your first wee of the day as it is more concentrated,” Periwinkle advises.
And she’s right. “Be aware that the timing of the urine sample can have an effect. It’s most accurate to test first thing in the morning – so always try to test yourself then,” says Nikki.
The best way to wee on your stick is with your very first urine of the day – your first morning urine (FMU as it’s called). This is when the hCG will be most concentrated in urine, and so easiest to detect.
3. Your wee is too diluted
Don’t drink lots of water or other liquids in the couple of hours before testing, as this will dilute your urine. Try to hold on, for as long as is comfy, before weeing and pee straight on to the stick.
4. There’s a chance you’re not pregnant
Even though other factors might point to you being pregnant, as Nikki says, “the test may have shown a negative result because you’re not actually pregnant” .
“If you’ve missed your period and are experiencing pregnancy symptoms (here’s a reminder of those early pregnancy symptoms) but have a negative pregnancy test result, ask your GP for a blood test to check your hormone levels, which should help to clarify the situation.”
Occasionally you may get a very faint line on your pregnancy test, which can be difficult to interpret, which is exactly what happened to mum heartsbeats03 on our forum: “My husband and I have been trying to conceive. The last 3 days my breasts have been tingling and sore.
“I also have been having very bad headaches and been very sleepy. It has been 4 weeks from the first day or my last mc [menstrual cycle]. I took a pregnancy test and there was an extremely faint line. Does this mean that I am pregnant?”
If you remain unsure about whether or not you are pregnant, always consult a health professional.