Can a Pregnancy Test Be Wrong? Understanding False Positives and False Negatives

Taking a home pregnancy test can be a stressful or exciting moment. But what happens when the result doesn’t match how you’re feeling—or what’s actually happening? While home pregnancy tests are usually reliable, they’re not perfect. You can get a false positive (a test says you’re pregnant when you’re not) or a false negative (a test says you’re not pregnant when you are).

At BASS Medical Group, we want to help you understand the difference between these two outcomes—and what to do next if you’re unsure.

What Is a False Positive Pregnancy Test?

A false positive occurs when a test incorrectly detects pregnancy. This can happen when something interferes with the hormone the test is trying to measure: human chorionic gonadotropin (hCG).

Possible causes of a false positive:

• Recent miscarriage or abortion: hCG can stay in your body for weeks after.
• Certain medications: Fertility treatments or hCG-trigger shots may affect results.
• Medical conditions: Rare conditions like ovarian cysts or certain cancers may elevate hCG.
• Evaporation lines: Faint lines that appear after the test window has passed can be misleading.

While false positives are less common than false negatives, they can still occur—especially if the test isn’t used correctly or read too late.

What Is a False Negative Pregnancy Test?

A false negative is more common and happens when a test fails to detect pregnancy, even though you are pregnant.

Common reasons include:

• Testing too early: It takes time for hCG levels to rise. Testing before a missed period may result in a negative.
• Diluted urine: Drinking a lot of fluids before testing can lower hCG concentration.
• Expired or faulty test: Always check the expiration date.
• Improper testing: Not following instructions can affect accuracy.

If your period is late but the test is negative, try testing again in a few days or contact your provider for a blood test.

What to Do If You’re Unsure About Your Results

If your pregnancy test result doesn’t match your symptoms—or you’re confused by a faint line—the best next step is to contact your Primary Care Provider (PCP) or OB-GYN. A blood test and follow-up visit can confirm whether or not you’re pregnant and rule out any underlying conditions.

At BASS Medical Group, we offer supportive, confidential care to help you navigate early pregnancy concerns, fertility, and reproductive health.

How to Get the Most Accurate Pregnancy Test Results

• Test first thing in the morning (when hCG is highest)
• Don’t drink excessive fluids before testing
• Read the result within the test’s suggested time window
• Use a digital test if you're unsure about lines

When to See a Doctor

• You’ve had multiple conflicting results
• Your period is more than a week late
• You’re experiencing symptoms of pregnancy (nausea, fatigue, breast tenderness)
• You’ve had a miscarriage or recent fertility treatments

We’re here to help you get clarity and peace of mind.

Schedule a Visit Today

If you're unsure about a home pregnancy test result, trust the experts at BASS Medical Group. Our team provides accurate testing, personalized advice, and compassionate care for women at every stage of reproductive health.