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, your excitement may turn to confusion as you 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 faint positive line, there’s a strong possibility that you’re pregnant. Some women see a clearly distinguishable positive line after taking a home test. 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.
You’re not pregnant:
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.
You were pregnant: Early pregnancy loss
Unfortunately, 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 good news 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.
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.
How often would you recommend women take a pregnancy test if they are trying to conceive?
I would suggest they take a home pregnancy test if they are “late” for their normal menstrual cycle. Most tests now are sensitive to even being a few days late. If it’s definitively positive, no other home test should be required. If it is questionably positive or negative, a repeat in two to three days would be appropriate. If there is still a question, I would recommend a urine or blood test at a doctor’s office. Most doctors will repeat the test at the first office visit to confirm the home test.Michael Weber, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.