Positive pregnancy test then negative a week later no bleeding

The time between when a woman suspects she might be pregnant and when it is confirmed for sure is the longest of her life. Regardless of whether you are hoping for a positive or a negative result, the odds are good that you are sweating bullets when the time to read the pregnancy test finally comes. And the wait isn't necessarily over upon seeing a result the first time; many women take the test several more times just to be certain. So what happens if you get a different result the next day? Can a pregnancy test change overnight? The answer is yes.

Why would a negative pregnancy test turn positive overnight?

Not only can you get a negative pregnancy test result followed by a positive, but you can also get a positive test result and then a negative. If you take an at-home pregnancy test one morning to find a negative result, it could mean that you’re not pregnant, or it may be that you’re taking the test too early. To wrap your head around this further, it’s helpful to know what pregnancy tests are even looking for. At-home pregnancy tests display results based on the level of human chorionic gonadotropin hormone (hCG, the pregnancy hormone, detected in your urine). If your numbers are elevated, the pregnancy test will show a positive result. If not, you’ll see a negative result. Most doctors recommend that you wait until after your missed period to take an at-home test, which can be difficult to do if you’ve been trying to conceive for some time. The reason why it helps to wait is because hCG increases throughout your first trimester, so the earlier you take the test, the higher the margin for error because you haven’t given your body enough time to hit the minimum amount of hCG needed to trigger a positive test result.

So the explanation for a negative test changing to positive overnight is pretty straightforward and simple. But what about a positive test changing to negative? What does it mean?

Why would a positive pregnancy test turn negative the next day?

Dr. Yvonne Bohn, an OB-GYN with Los Angeles Obstetricians and Gynecologists in Santa Monica, California, explains to Romper that this is likely a sign of a chemical pregnancy. "A chemical pregnancy is a very early pregnancy that usually ends about a week after the missed menstrual cycle," explains Dr. Bohn. "In a chemical pregnancy, the hormones of pregnancy are very low and the pregnancy doesn’t develop. The body recognizes and induces a very early miscarriage which is like a delayed menses.”

In cases of chemical pregnancies, Dr. Bohn explains that the pregnancy test result will usually be a faint positive the first time but the follow-up tests will probably come out negative. Makes sense if the amount of the specific chemical the test is detecting in your urine drops when the pregnancy is not viable. Additionally, you will often know that the pregnancy is failing because of menstrual-like bleeding. She says that medical care is usually not necessary in such instances, as the bleeding should be like a heavy period and then end, but if you experience severe pain or heavier bleeding, you should be seen by a physician.

Let’s be clear: The miscarrying of a chemical pregnancy has nothing to do with what you did or didn’t do, and it is not your fault. Bohn explains that the pregnancy is not genetically normal so it simply does not continue to grow, and that’s why your body will induce a miscarriage on its own. Yet this can understandably be an emotionally distressing experience for any person to go through, especially if she was celebrating being pregnant only the day before. She also shares that the chance of miscarriage may be reduced by taking proactive measures if you are trying to conceive, such as taking prenatal vitamins or folic acid, avoiding high substance use, and controlling preexisting medical conditions effectively.

For many women, one at-home pregnancy test is not enough to confirm that they are pregnant (there’s a reason why test brands don’t advertise themselves as being 100% accurate, after all), let alone that the pregnancy is healthy and will be carried through. Sure, a subsequent pregnancy test (or more) a couple days later can confirm (or contradict) initial results, but the best way to get the most accurate reading is to call your medical provider to get a blood test, followed by an ultrasound. At-home tests are an advancement certainly convenient for the modern woman, but we have to remember that they should be backed up by a professional.

Expert:

Dr. Yvonne Bohn, OB-GYN with Los Angeles Obstetricians and Gynecologists in Santa Monica, California

This article was originally published on Feb. 18, 2018

No matter what, taking a pregnancy test can be an emotional roller coaster. When it comes to getting a false positive pregnancy test result, the experience can be deeply upsetting, particularly for anyone who has had a difficult time getting pregnant or is actively hoping to get pregnant (or both). The hope that comes with seeing that positive sign crashing down as you realize it was a false positive pregnancy test? It's a uniquely devastating emotion. 

Of course, getting a false positive pregnancy test when you’re actively trying not to get pregnant can be just as horrible. Yup, you could probably do without the panicked verification trip to the ob-gyn, just to learn there was nothing to stress over. 

Thankfully, experts note that false positive pregnancy tests are rare. Unfortunately, though, they can happen. Here are some of the most common causes of a false positive pregnancy test, along with some additional information that can help you put it all into context.

First, what is a pregnancy test?

Let's start with the absolute basics just to make sure we're all on the same page. A pregnancy test tells you if you’re pregnant or not. That's simple enough to understand. But it's understandable if you're a little fuzzy on the details of what these devices actually look for to identify a pregnancy.

At-home pregnancy tests check for the hormone hCG. HCG is short for human chorionic gonadotropin, which the body creates during pregnancy. Right after a fertilized egg attaches to the uterine lining, the placenta then forms and starts producing hCG1. A blood test can detect hCG about nine days after conception, and a urine test can detect it 12 to 14 days after conception, according to the Cleveland Clinic, although it varies—some especially sensitive urine tests can detect a pregnancy even earlier. A person’s hCG level typically doubles every 72 hours through 8 to 11 weeks of pregnancy. Then it remains consistent and starts to go down after delivery.

Back to top.

How does a pregnancy test work?

An at-home pregnancy test is designed to find hCG in pee2. If the hormone is present, it triggers a chemical reaction and the test signals that you're pregnant. If hCG is not present, the test will say you aren't pregnant. Many tests use two lines to mean you’re pregnant and one line to mean you’re not—but it depends on the test brand. Some tests use plus and minus signs. Some digital pregnancy tests have a screen that plainly reads "pregnant" or "not pregnant." Which can save you some “Is that one line or two?!” squinting, at least.

Seems simple, right? As Ina Garten would say, "How easy is that?" Typically, pretty easy. Most at-home pregnancy tests claim to be about 99% accurate3. Ultrasounds typically can't detect a pregnancy until a little later in your pregnancy and that's why at-home tests are so useful. But, sometimes, other elements can mess with a pregnancy test's results and tell you you’re pregnant when you’re really not. 

Back to top.

What can cause a false positive pregnancy test?

Here are the most likely reasons you may end up with a false positive pregnancy test:

1. You let the test sit too long before looking.

If you take a standard pregnancy test with line indicators, it's important to check the results according to the specific instruction of the test. If you let it sit too long before reading the results, urine on the test can evaporate and make it look like you have two lines instead of just one. "Oftentimes people will see evaporation lines as urine starts to evaporate off the test," Jamil Abdur-Rahman, M.D., board-certified ob-gyn, tells SELF. That might cause the test to look like it has a faint second line—making it positive—but it really only has one.

The best way to avoid this: Read the pregnancy test's directions and follow them exactly. The popular pregnancy test brand First Response, for example, instructs users to wait three minutes after taking the test, then read it as soon as possible4.

2. The pregnancy test is expired.

The second most common reason Dr. Abdur-Rahman's patients get false positives is because the test is expired, he says. When a test is past its expiration date, the chemical that detects hCG doesn't always work as it should, and you’re more likely to get a misread. "The test can expire and the chance of having a false positive increases," Dr. Abdur-Rahman says.

3. You’re on fertility medications that raise hCG levels.

If you take a pregnancy test too soon after taking a fertility drug that contains hCG—like some injections that are often part of in vitro fertilization—you could get a false positive.

Can you get a positive pregnancy test and then a negative and still be pregnant?

Why do I keep getting positive then negative pregnancy tests?

Can you have a miscarriage without bleeding?

Can I still be pregnant