If you’re desperate to know whether you’re expecting then the wait to get an accurate pregnancy test can feel like a lifetime. I can remember taking tests almost every day even though I knew it was still too soon to find out. If you want to know the best ways to get accurate pregnancy test readings, or can 12 hours make a difference in a pregnancy test result then keep reading.
Can 12 Hours Make a Difference in a Pregnancy Test or Even Overnight?
If you are wondering can 12 hours make a difference in a pregnancy test then the quick answer is yes it can change the result but it doesn’t mean that the new result is correct. When you first take a pregnancy test a positive result will show if your urine has produced a level of the hormone human chorionic gonadotropin (hCG) and these levels will increase throughout the first trimester of pregnancy. If your pregnancy test has changed overnight then this is usually caused by the chemical composition of your urine sample changing due to the test’s evaporation line and this may display a false positive, which is why it is suggested you discard any readings on your pregnancy test after around 10-15 minutes.
How Can a Pregnancy Test Change in 12 hours?
If you have ever thrown away a negative pregnancy test to only discover a faint positive line on it hours, or even days later then you might start to panic that you’ve got it all wrong. Even if you have waited until after your period is due to get accurate test results, it can still be a big surprise to see a positive line when you thought quite the opposite.
Whatever brand of at-home pregnancy tests you take, they will all have important instructions you need to follow and most suggest you wait a small amount of time before checking the results window to determine a positive or negative result. These tests that show two lines to indicate a positive test have two hidden “indent” lines where the ink pools for the control and positive lines.
As the urine comes into contact with the reactive paper, if the hormone hCG is detected then this will move the ink across the two lines and display a positive test. Usually, a test will recommend you read the result within 5-10 minutes of taking the test as this is when it is at its most accurate, but can 12 hours make a difference in a pregnancy test?
Well, it can if you are reading the result 12 hours after taking the test but this is not down to you actually being pregnant this is due to something called an evaporation line.
Evaporation Line
This is where something known as an evaporation line comes into play. Unfortunately, this faint line can appear after a negative test has been read and cause some confusion about whether you are pregnant or not.
As the urine in the test dries, the ink can move across the screen and gets caught in the indent line and the caught ink will be pulled to the surface and become darker. Evaporation lines look like a colorless or grey streak in comparison to the control line, but this can cause some confusion when reading your test if the lines are already blue. These lines often appear thinner and more uneven compared to the control line which can help you to identify the difference between a false positive reading.
This is why it is suggested that pregnancy tests are considered invalid after the allotted time as you can only get accurate readings within the specified time frame.
The Line is Smudged on My Pregnancy Test
Smudged lines on your pregnancy test that are barely visible can indicate that you are very early in your pregnancy.
To be 100% positive that you are getting the correct result you will need to retake your test at a later date to get a more accurate reading.
Can Pregnancy Tests Change Overnight?
If you have struggled to wait before taking a pregnancy test then you will know that an accurate reading might be more difficult to come by just yet. It can be tempting to take a test every day if you are eager to know, especially with some brands of pregnancy tests claiming they are sensitive enough to provide positive results as early as five days before your expected period.
Although some women might have produced enough hCG to get a positive result, not everyone will that early on as the amount of hCG in the urine varies from one woman to another. Testing too soon can cause a false-negative result and this may cause more confusion.
There is a common misconception that taking a pregnancy test in the late evening or before bed can produce a higher chance of getting a positive result, but this isn’t as true as you may think! As your pregnancy test needs to detect the hormone levels in your urine, the best time to test is first thing in the morning as there is a more concentrated amount of hCG present.
This doesn’t mean your result can necessarily change overnight, but retaking your test in the morning so your body has time to produce higher levels of hCG could be the difference between a false negative and a real one!
Wrapping Up
So can 12 hours make a difference in a pregnancy test? It can make a difference to your results but that does not mean that the result you get is then accurate. With the possibility of evaporation lines producing false-positive tests, it is easy to see why so many women get confused when taking at-home pregnancy tests. If you are ever unsure of your test results or need more help, seek advice from your medical provider.
The best way to get the most accurate reading from your pregnancy test is to wait until your period is due to give your body a chance to produce the correct levels of the hCG hormone. You should also only read your test results during the suggested time frame given in your instructions (usually no more than 10 minutes) as any longer and the results will be invalid.
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