Can you get a positive pregnancy test before missed period

Early pregnancy tests are designed to tell whether you're pregnant five days before you miss your period. These sensitive tests aim to detect a hormone produced during pregnancy earlier than standard ones. But do they really work? Learn about these tests and how they compare to regular pregnancy tests.

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Can you get a positive test before missing your period?
How accurate is a positive pregnancy test before missed period?

First, a pregnancy test primer: Whether it's a blood test or a urine test done at a healthcare provider's office or in your bathroom, a pregnancy test is positive when it detects the hormone human chorionic gonadotropin (hCG)—a hormone produced by placental cells during pregnancy—in your system, according to John Hopkins Medicine.

The production of even a tiny amount of hCG means the fertilized egg has been implanted in the uterine lining.

The variance between at-home pregnancy tests is the amount of hCG they can detect, with early pregnancy tests detecting lower hormone levels.

"The commercial pregnancy tests range from 20 to 50 mIU/mL. Since hCG levels double every two to three days, some tests may detect hCG two to three days earlier—so there may be some benefit to using a more sensitive test," said Seth Guller, PhD, the director of the Gyn/Endocrine Laboratory at the Yale School of Medicine.

Guller added a surprising caveat: Any benefits of early pregnancy detection should be balanced by the fact that most pregnancies ending in miscarriage—or sudden pregnancy loss before 20 weeks—occur during the first seven weeks of pregnancy, according to MedlinePlus.

Knowing if you're pregnant early allows you to promptly make educated health and lifestyle changes that can increase the chance of delivering a healthy baby. This could include smoking cessation, getting vaccinations, and ensuring a healthy weight, according to the Centers for Disease Control and Prevention (CDC).

Charles Lockwood, MD, the chief of obstetrics and gynecology at Yale-New Haven Hospital, adds that "the risk of exposure to agents causing birth defects doesn't start until two weeks after conception."

There is no denying that trying to conceive is suspenseful. This is why a person might want to know about pregnancy as soon as possible—despite the emotional risk of learning about brief chemical pregnancies, which are miscarriages that occur within the first five weeks.

There are biological factors that may affect the results of these tests. These super-sensitive tests claim to identify a pregnancy a whole week before a missed period, but embryos can fully implant (and start producing hCG) at different times. So, even if you're using the most sensitive test, your embryo may not immediately produce a positive pregnancy test. It may take several days.

"Embryo implantation is a process that unfolds over a number of days rather than a single event," said Hugh S. Taylor, MD, the chief of reproductive endocrinology and infertility at the Yale School of Medicine.

According to UCSF Health, it can take up to six days after fertilization for the embryo to become a blastocyst (mass of well-organized cells) and begin the implantation process.

"Embryos do grow at different rates; they can vary by about one day prior to implantation," Dr. Taylor said. "Pregnancy tests vary by the growth rate of the embryo and because of maternal body size and hydration status."

So every person may test positive on a different day, regardless of how fancy the test may be. Ultimately, it's up to you to decide if waiting to find out works for you or not.

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Missing a period is one of the first signs that you might be pregnant. You may take a home pregnancy test as soon as possible. If you have very early pregnancy symptoms, such as implantation bleeding, you may even take a home pregnancy test before your first missed period.

Some pregnancy tests are more sensitive than others and can accurately detect a pregnancy several days before a missed period. But after taking a home test, you may notice a faint positive line.

With some home pregnancy tests, one line means the test is negative and you’re not pregnant, and two lines mean the test is positive and you are pregnant. A faint positive line in the results window, on the other hand, can leave you scratching your head.

A faint positive line isn’t uncommon and there are a few possible explanations.

If you take a home pregnancy test and the results reveal a clearly distinguishable positive line, there’s a strong possibility that you’re pregnant.

But in other cases, the positive line appears faded. In these instances, a faint positive can be caused by low levels of the pregnancy hormone human chorionic gonadotropin (hCG).

As soon as you become pregnant, your body begins producing hCG. The hormone level increases as your pregnancy progresses.

Home pregnancy tests are designed to detect this hormone. If hCG is present in your urine, you’ll have a positive test result. It’s important to note that the more hCG in your system, the easier it is to see and read a positive line on a home test.

Some women take a home pregnancy test early in their pregnancies. They often take them before or shortly after their first missed period.

Although hCG is present in their urine, they have a lower level of the hormone, resulting in a positive pregnancy test with a faint line. These women are pregnant, but they’re not far along in the pregnancy.

Keep in mind that not all home urine pregnancy test are this accurate. You may want to consider taking a repeat urine pregnancy test and seeing whether you get a more definitive result.

Taking a home pregnancy test and getting a faint positive line doesn’t always mean you’re pregnant. Sometimes, what appears to be a positive line is actually an evaporation line. These misleading lines can appear in the results window as urine evaporates from the stick.

If a faint evaporation line develops on your home pregnancy test, you may mistakenly think that you’re pregnant.

It can be hard to determine whether a faint line is a positive result or an evaporation line. The primary difference is that evaporation lines appear in the test window several minutes after the recommended time for checking the test results.

If you take a home pregnancy test, it’s important to read and carefully follow the instructions. The package will let you know when to check your test results, which can be within three to five minutes, depending on the manufacturer.

If you check your results within the recommended time frame and see a faint positive line, you’re most likely pregnant.

On the other hand, if you miss the window for checking the results and you don’t check the test until 10 minutes later, a faint line may be an evaporation line, which means you’re not pregnant.

If there’s any confusion about whether a faint line is a positive line or an evaporation line, retake the test. If possible, wait two or three days before taking another one.

If you are pregnant, this gives your body additional time to produce more of the pregnancy hormone, which can result in a clear, undeniable positive line.

It also helps to take the home pregnancy test first thing in the morning. The less diluted your urine, the better. Make sure you check the results within the appropriate time frame to avoid confusing an evaporation line with a positive line.

A faint positive line can also be a sign of a very early miscarriage, sometimes called a chemical pregnancy, which occurs within the first 12 weeks of a pregnancy, often much earlier.

If you take a home pregnancy test after a miscarriage, your test may reveal a faint positive line. This is because your body may have residual pregnancy hormone in its system, although you’re no longer expecting.

You may experience bleeding that resembles your menstrual cycle and light cramping. Bleeding can occur around the time when you expect your next period, so you may never know of the early miscarriage.

But if you take a home pregnancy test while bleeding and the results show a faint positive line, you may have had a pregnancy loss.

There’s no specific treatment, but you can talk with your doctor if you suspect a miscarriage.

Early pregnancy losses are not uncommon and occur in about 50 to 75 percent of all miscarriages. These miscarriages are often due to abnormalities in a fertilized egg.

The truth is that women who have had a very early pregnancy loss don’t necessarily have problems conceiving at a later time. Many women eventually have healthy babies, although recurrent pregnancy loss is a reason for further evaluation.

If you’re unsure whether a faint line on a pregnancy test is a positive result, take another home test in a couple of days, or make an appointment with your doctor for an in-office pregnancy test.

Your doctor can take a urine or blood sample and more accurately determine whether a pregnancy has occurred. If you think you had a very early miscarriage, let your doctor know.

Read more: 5 signs you should take a pregnancy test »

Can you get a positive test before missing your period?

Early Detection The most sensitive tests on the market can potentially give you a positive result four to five days before your period is due, meaning you don't necessarily have to wait for a missed period, or watch for other pregnancy symptoms, to find out whether you are pregnant.

How accurate is a positive pregnancy test before missed period?

This is why pregnancy test manufacturers advertise the way they do: “Know four days sooner,” or “Accurate up to six days before a missed period.” However, while home pregnancy tests are quite accurate – many boast a 99% detection rate based on laboratory testing results – marketing claims can be misleading.