What Causes a False Negative on a Pregnancy Test?
So you think you're pregnant, but the home pregnancy test came out with a big fat negative (BFN)? Every day I hear from women who believe that they are pregnant, but who have tested and received negative results on the pregnancy test they chose. For those hoping to be pregnant, this can be frustrating, and many women don't trust the results of these tests, particularly when they continue to have symptoms of early pregnancy.
Chances are very good that if you've gotten a negative pregnancy test, you are not pregnant. I cannot diagnose pregnancy over the internet, and I am not a medical doctor, but I'm here to help you as much as possible to determine the potential causes of a negative pregnancy test.
I've included some recommended brands of pregnancy test on this page in order to help you to choose a test with a higher sensitivity which is therefore more likely to help you to determine whether or not you are pregnant. My regular resource for information on this subject is unavailable, so I've researched the sensitivity of these pregnancy tests the long (and hard) way.
Please note that I am not a medical professional. If you believe you are pregnant, but pregnancy tests show negative results, you should contact your doctor for further advice!
These are the most sensitive tests that you can purchase on Amazon, detecting pregnancy at 20 mIU.
How do Pregnancy Tests Work?
Pregnancy tests work by detecting the pregnancy hormone hCG in your urine. Any home pregnancy test should be accurate, depending on the amount of the pregnancy hormone that is in your urine and the sensitivity of the test. A more sensitive test will detect the hormone at lower levels than a less sensitive pregnancy test.
Price does not indicate the sensitivity of your pregnancy test.
For example, the Equate pregnancy tests, which are available at Wal*mart, are sensitive to 25 mIU, which is the same sensitivity as the EPT.
Don't assume that your test has given you a negative result because you purchased a "cheapie" test. This reference should help you to determine whether your brand of test is sensitive enough to detect early pregnancy.
How to Read a Pregnancy Test
Home pregnancy tests should be relatively simple to use. A standard test (non-digital), contains a test strip, which a hopeful woman urinates on in order to saturate the stick. Different tests require different amounts of urine, so always read your instructions!
The strip wicks the urine up the strip. If you are pregnant, two lines will appear: the variable line (which indicates pregnancy) and the control line (which indicates that your test has worked correctly).
If two lines appear, you are pregnant. It doesn't matter how faint the variable line is, a line is a line, and you are pregnant.
I Think I See a Line, but I'm Not Sure?
Every women who is trying to conceive has had at least one test at some point in time which has her stumped. This is usually due to the habit of testing too early, but there is a solution to this problem. Follow these steps to check to make sure that you are seeing a line.
- Break open the plastic casing on your pregnancy test, and pull out the test strip. If you didn't have casing on your strip, then simply take the strip.
- Take a photograph of your test strip. Get it up close and make sure that your photograph is clear and illustrates the line you think you're seeing.
- Load the photograph into your computer, and load up your image editing program. If you don't have one, GIMP is free.
- Go to "colors" and then "invert" in order to invert the colors of your image.
If there the test is positive, the line will be clear now! The above image is "no derivatives" which means that I can't edit this image, but if you want to use it as a tester, to load into your graphics program and invert the image, you'll be able to see what I mean. I've already tested it and have personally used this method to confirm faint positives.
Tested Too Early
Too Little Hormone
Wait Two Days and Test Again
Try a Different Brand
Test with FMU
Try a More Sensitive Test
Test with FMU
Try a Different Brand
Try a Different Brand
You Might Get a False Negative Pregnancy Test If: You Tested too Early
Your body won't begin to produce the pregnancy hormone until the embryo has implanted on the wall of your uterus. This implantation signals your body to begin producing the hormone which will cause your body to supply nutrients to the baby and to nourish the embryo.
If you're trying to conceive, I recommend learning to track your ovulations. Doing this will help you to determine the best time to test.
Implantation occurs between 8 and 10 days following your ovulation. If you are tracking your ovulations, implantation should be indicated by a dip in your temperature, followed by a steady rise. The rise in temperature is a strong indication of pregnancy, particularly if it follows this dip. I've recommended a Basal Body Thermometer on the bottom right. Should you choose to temp for your ovulation and possible early pregnancy, you need a basal body thermometer since it detects the smallest of changes in your body temperature.
How Early Can You Take a Home Pregnancy Test for Accurate Results?
The earliest that you should take a home pregnancy test and expect accurate results is about fourteen days past ovulation (d.p.o.). This is why it's so important that you learn to track your ovulations if you're trying to conceive (or even if you're trying to avoid pregnancy. I've recommended a good basal body thermometer to the right. The listed thermometer is highly rated and relatively inexpensive. Make sure not to purchase a scanning thermometer. You must purchase oral to get accurate results!
You Might Get a False Negative Pregnancy Test If: Your Test isn't Sensitive Enough
The key to getting accurate results early is to make sure that you are using the most sensitive pregnancy tests available to you. I've recommended one brand that can be purchased in bulk discreetly on Amazon above (if you're trying to conceive, this is recommended), but I would also like to point American women in the direction of the New Choice pregnancy test, which is available at the Dollar Tree. Yes, this $1 test is among the most accurate you can buy. Here is one source on the matter.
You don't have to spend a lot of money to get a sensitive test. I highly recommend purchasing one of the less expensive tests, as they are often more sensitive than their more expensive brethren.
You Might Get a False Negative Pregnancy Test If: There Isn't Enough hCG in Your Urine
It's always best, particularly if testing early, that you use your first morning urine when taking a pregnancy test. The amount of hCG in your first morning urine is higher than it is when you've been using the restroom regularly.
Note that "first morning urine" (or fmu) refers to urine which is passed five hours subsequent (after) the last time you urinated. So if you wait five hours after using the restroom, this counts as first morning urine. A three hour nap won't do the trick. You will absolutely need to wait five hours or more before testing if you want the most accurate results from your home pregnancy test.
You Might Get a False Negative Pregnancy Test If: You've Taken the Test Wrong
Each test that you purchase will have specific instructions. In most cases, modern tests instruct you to urinate on a stick which will wick the urine up the stick and detect the hormone in your urine. In other cases, you are asked to dip a test strip into a cup of your urine in order to test for pregnancy. In either case, too much or too little urine will result in an inaccurate result -- generally a false negative, as opposed to a false positive.
It's recommended that you purchase more than one pregnancy test in the case that you make a mistake. I personally like the New Choice tests because they come with a pipette which allows you to drop the urine into the screen rather than dipping or urinating on the stick. This is a more foolproof method. Bonus: The tests are some of the most sensitive on the market!
Trying to Conceive? Helpful Information
- Am I Pregnant? How to Tell if You're Pregnant
Most women who are trying to conceive want to know right away whether or not they're pregnant. If you're in the monstrous two week wait, maybe there are symptoms of pregnancy before you test.
- Trying to Conceive? Learn to Track Your Ovulations
If you're trying to become pregnant, it will help if you know how the female cycle works. This article will explain how to track your ovulation and help you to understand when to expect your period.
Feel free to ask me questions relating to pregnancy tests and to early pregnancy. I am not a doctor, but I will do my best to answer your questions. Please ensure that you have read this article and the two listed to the right before asking questions about your menstrual cycle and early symptoms.
Remember that I'm not a doctor, and therefore if you continue to get negative pregnancy tests, but are convinced you are pregnant, you should see your doctor, as the video above suggests. This is important, because in rare cases a false negative could be an indication of a problem, such as ectopic pregnancy. If anything at all has you concerned about your health, contact your doctor immediately.
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