An early pregnancy test is designed to detect a specific hormone in your body that indicates pregnancy. However, how soon a test shows positive—and how accurate it is—depends on timing, test type, and how you use it.

Typically, urine tests are most accurate one to two weeks after a missed period, while blood tests performed by healthcare providers can detect pregnancy as early as six to eight days after ovulation.

For the most reliable results, take an at-home test in the morning, at least a week after your missed period, when hormone levels are most concentrated.

How Do Pregnancy Tests Work

Pregnancy tests detect the hormone human chorionic gonadotropin (hCG), which is released by placental cells shortly after the fertilized egg implants in the uterus.

Even a tiny amount of hCG can signal early pregnancy. However, not all tests are equally sensitive. Early-detection tests are designed to identify very low levels of hCG, allowing you to find out sooner—but not always accurately.

How Accurate Are Early Pregnancy Tests

Many early pregnancy tests claim they can detect pregnancy a day after a missed period, but research shows that accuracy varies widely at this stage.

Because hCG levels rise gradually in early pregnancy, testing too early may result in false negatives.

By contrast, blood tests are more precise and can detect hCG several days before a missed period, making them the most reliable option for early confirmation.

Keep in mind that certain factors—like chemical pregnancy (a very early loss) or testing errors—can also affect accuracy.

Factors That Can Affect Accuracy

Several variables can influence how accurate your pregnancy test result is. These include:

  • Timing of the test: Testing too soon after ovulation can yield false negatives.

  • hCG concentration in urine: Testing with diluted urine (such as later in the day) may reduce accuracy.

  • Expired test kits: Using a test past its expiration date can lead to errors.

  • Fertility medications: Drugs containing hCG can produce false positives.

  • Incorrect use: Not following directions precisely may skew results.

  • Type of test: Some brands are more sensitive to hCG levels than others.

How Soon Can Pregnancy Be Detected

In most cases, an at-home pregnancy test can detect pregnancy 12–15 days after ovulation—roughly one to two weeks after a missed period if your menstrual cycle is about 28 days.

A blood test, however, can detect pregnancy 6–8 days after ovulation, since it identifies smaller amounts of hCG than urine-based tests.

When Should I Take an Early Pregnancy Test

If you think you might be pregnant and are noticing early symptoms—such as a missed period, fatigue, nausea, or breast tenderness—taking a test can help you find out sooner.

You may consider an early pregnancy test if you want to:

  • Adjust your lifestyle or medications: Some drugs, supplements, and herbs are unsafe during pregnancy, and it’s important to avoid alcohol or tobacco once you’re expecting.

  • Make informed contraceptive decisions: If your test is negative after unprotected sex, you might consider emergency contraception, which can prevent pregnancy if taken within five days.

  • Begin prenatal care early: Confirming your pregnancy allows you to start prenatal visits, essential for monitoring your health and your baby’s development.

What Time Should I Take the Test

For best results, use first-morning urine, which contains the highest concentration of hCG. Testing too late in the day may dilute hormone levels and reduce accuracy.

Even if you use an early-detection test, try to wait at least one week after your missed period before testing. This timing minimizes the chance of a false result.

When To See a Healthcare Provider

If you’ve taken a test and believe you’re pregnant, it’s important to schedule a visit with your healthcare provider. They can confirm the result with a blood test or ultrasound and ensure you receive proper prenatal care.

Seek medical attention immediately if you experience any of the following symptoms during pregnancy:

  • Decreased baby movement after week 28

  • Severe or persistent abdominal pain

  • Fever, chills, or burning during urination

  • Severe headaches or vision problems

  • Sudden swelling of the face, hands, or fingers

  • Heavy vaginal bleeding or fluid leakage

  • Persistent vomiting or dehydration

  • Thoughts of self-harm or harm to your baby

Early medical care can protect both your health and your baby’s well-being.

A Quick Review

Early pregnancy tests can detect hCG—the key pregnancy hormone—but their accuracy depends on timing and proper use.

  • Urine tests work best one week after a missed period.

  • Blood tests can confirm pregnancy earlier—about six to eight days after ovulation.

  • Testing too soon or using expired kits may cause false negatives or false positives.

If you suspect you’re pregnant, confirm with a healthcare provider to ensure accurate results and begin prenatal care promptly.