Pregnancy

Negative Pregnancy Test: What It Means & Possible Reasons For Your Missed Period

Updated on
negative pregnancy test

 

Overview

Did you get a negative pregnancy test but already missed your period or feel pregnant? It might have been a false negative pregnancy test. But it’s also possible you might not be pregnant, even if your period is late.

A 2021 Journal of the American College of Emergency Physicians (JACEP) Open study showed that false negative pregnancy results are uncommon, only comprising around 1.6% of all test results. (1)

Surprisingly, only around 7% of the false negatives were linked to ectopic pregnancy. Most were intrauterine pregnancies (41.5%) or abnormal pregnancies (45%). (1)

Other researchers noted that some false negative results were due to multiple pregnancies (e.g., twins or other multiples). For example, a 2022 Cureus case study detailed how a woman who previously tested negative was found via ultrasound to be 8 weeks pregnant with twins. (2)

Other studies also found that false negative results were more common when the tests were done too soon, such as on the first day or week of a missed period. (3)(4)(5)

Can you trust the accuracy of home pregnancy test kits? What should you do if you keep getting negative results but feel you’re pregnant? Do false positive results also happen with at-home pregnancy tests? When must you go to an OB/GYN or healthcare provider for medical advice? Are there other confirmatory tests you can take if you suspect you’re pregnant?

We’ll answer these questions below. We’ll also discuss some of the primary reasons why you’re getting a false negative result and the possible causes of late periods even if you aren’t pregnant.

 

How Do Home Pregnancy Test Kits Work?

When you conceive, the trophoblastic tissue (from the zygote or fertilized egg) produces hCG (human chorionic gonadotropin upon implantation. Also called the pregnancy hormone, hCG helps the embryo’s development and promotes the creation of the placenta. (3)

Pregnancy test kits usually check for the presence of the hCG hormone’s beta subunit, with most being accurate enough to detect beta subunits within 25 to 50 mIU/ml. Other tests might be sensitive enough to detect hCG hormones at 15 mIU/ml, while others might be less sensitive and need at least 15 to 100 mIU/ml. (3)

 

What Does A Positive Test Result Mean & Can It Ever Be Wrong?

  • You might be pregnant
  • It can also be a false positive (explained below)

 

False Positives & Early Pregnancy Complications Or Problems

Although rare, false positive pregnancy results can also happen, particularly if you’ve undergone fertility treatments (e.g., hCG injections). (7)

You can also get a positive pregnancy result with the following, even if you lose the baby: (1)

 

In these cases, you didn’t get a false positive. Your body might have already produced enough levels of hCG for the test kits to detect before you lost your baby.

 

What Does A Negative Test Result Mean & Can It Ever Be Wrong?

  • You might not be pregnant
  • It can also be a false negative (explained below)

 

Are Home Pregnancy Tests Accurate?

At-home pregnancy test kits are fairly accurate, especially in recent years. Although they had a false-negative rate of around 24.3% in the 1980s, the number greatly decreased to around 1.6% in the 2020s. (1)(6)

However, the urine pregnancy test kits aren’t fail-proof. They still rely on the amount of hCG to detect a pregnancy, which depends on several factors (discussed below). 

 

Can You Be Pregnant But Still Test Negative?

Yes. It’s called a false negative pregnancy result. 

hCG multiplies quickly as your pregnancy progresses, but the amount can vary greatly among women or even between your pregnancies. (5)

The levels of hCG might still be too low to be detected during the first pregnancy weeks, potentially causing negative results. (3)(5)

Here are the typical hCG levels based on pregnancy weeks: (5)

(source: flo.health) (5)

 

How To Use A Home Pregnancy Test Kit

Kits can vary – some are even digital. Always check the manufacturer’s instructions and recommendations.

Most kits work this way:

  1. You pee in a cup or container.
  2. You use the test kit’s dipstick or dropper.
  3. Wait for the results after the recommended time.

 

Can Using Too Much Pee Cause A Negative Pregnancy Test Result?

It’s unlikely that too much urine can affect the test results.

 

When’s The Best Time To Take A Home Pregnancy Test?

  • At least one day after a missed period or menstruation (with or without early signs of pregnancy)
  • First thing in the morning, using your first urine

 

Can You Be Seven Weeks Pregnant And Test Negative?

It’s rare, but you might still test negative even at 7 weeks of pregnancy, especially if you’re having twins (extremely high hCG levels ‘overload’ the test kit). Previous cases have been documented, including a woman confirmed pregnant via ultrasound at 8 weeks. (2)

 

Top Reasons Why Your Test Results Are Negative

Common Testing Errors & Mistakes

Testing Too Soon Or Too Early (Low Hormone Levels)

  • Your level of hCG hormones might still be low for the test kit to detect (3)(4)(5)

 

Testing Too Late In The Day

  • The amount of hCG is highest with your first-morning urine but can be lower at later times of the day due to dilution (more water in your urine)

 

Checking Results Too Soon Or Other Testing Procedure Error

  • You might have taken the dipstick off the urine sample quicker than the required time (we suggest using a timer and following the manufacturer’s recommended time)

 

Test Kit With Low Sensitivity

  • Some test kits require higher amounts of the hCG hormone to work (e.g., 100 mIU/ml), but your levels are still low (3)

 

Expired Pregnancy Test Kit

  • Check your test kit’s expiry date; expired kits might no longer work

 

Twin Or Multiple Pregnancies & The ‘Hook EffectFalse Negative Test

Some researchers have noticed that multiple pregnancies might cause false negative results. (2)

Your body rapidly produces more hCG hormones if you’re pregnant with multiples. The extremely elevated levels of hCG might ‘overload’ the pregnancy test kits, leading to the so-called ‘hook effect’ that causes false negative results. (2)

The ‘hook effect’ is also believed to cause negative test results for: (2)

  • Molar pregnancy (complete molar pregnancy causes abnormally high levels of hCG)
  • Gestational trophoblastic disease (rare tumors that develop from the trophoblastic cells produced during pregnancy)

 

Can Drugs & Medications Affect Pregnancy Test Results?

Yes, some might. Pregnancy test kits can show positive results if you’ve had treatments that include hCG. For example, hCG injections used for fertility treatment might be detected by the test kit. (7)(8)

According to the Mayo Clinic, however, most drugs and medications (even those for contraception) are unlikely to interfere with pregnancy test results. (9)

 

Why Is Your Pregnancy Test Negative, But You Have No Period?

A missed period is among the most common pregnancy symptoms. However, late periods might also be caused by other factors. (discussed below)

 

Miscalculated Or Irregular Menstrual Cycle

It’s more difficult to predict menstruation dates when you have irregular periods. However, even with regular ovulation cycles, miscalculations can also happen.

Consider checking whether you have miscalculated your menstrual cycle and thought you missed your period. 

 

Using Hormonal Birth Control

While contraceptives are unlikely to cause a false positive or negative pregnancy test, they can affect your hormone balance and make you skip ovulation. It can lead to skipped or late periods, making you think you might be pregnant even if you aren’t. (9)

 

Breastfeeding Can Affect Your Cycle

Postpartum recovery varies from one mom to another, but many breastfeeding moms experience a delay in getting their period back. It might be months before you ovulate again. (10)

Even if you get your period back, it might take a couple more months before your menstrual cycle returns to normal. 

 

Long-Term Causes: Medical Conditions That Can Affect Your Menstrual Cycle

Some women’s health or medical conditions that might disrupt your menstrual cycle: (11)

  • Anovulation or ovulatory dysfunction
  • PCOS (polycystic ovary syndrome)
  • POI (primary ovarian insufficiency) or early menopause (perimenopause)
  • Menopause
  • Thyroid problems (hypothyroidism or hyperthyroidism)
  • Type 2 diabetes
  • Cushing’s syndrome
  • Cancer
  • Reproductive system problems, including structural abnormalities (e.g., obstructions, scarring, or underdeveloped parts)

 

Although most medications, drugs, and treatment options are unlikely to affect pregnancy test results, some can disrupt your menstrual cycle and make you think you’re pregnant because you skipped your period. Some of these are: (11)

  • Cancer medications
  • Antidepressants
  • Blood pressure or antihypertensive medications
  • Antipsychotics
  • Anti-allergy medications

 

Lifestyle Factors & Habits That Can Affect Your Menstrual Cycle

The following can also cause period delays or disruptions: (11)

  • Extreme diet or an eating disorder
  • Stress (especially chronic stress) 
  • Sudden weight loss from excessive exercise

 

Possible Reasons For A Missed Period With Discharge

Here are possible reasons: (12)(13)

  • Delayed ovulation
  • Pregnancy (white discharge can indicate you’re pregnant, brownish discharge might mean implantation bleeding), and bright red or pinkish discharge can be pregnancy spotting)
  • Very light or skipped period from hormonal contraception
  • Miscarriage

 

Possible Reasons For A Missed Period With Cramps

Here are possible reasons: (13)

  • Delayed ovulation
  • Endometriosis (abnormal growth of uterine tissues outside the uterus)
  • Uterine fibroids and polyps
  • Ovarian cyst
  • Infections, such as PID (pelvic inflammatory disease)

 

What To Do After Taking A Pregnancy Test

If you are unsure of your test kit’s results or simply want to confirm them, you can go to the lab for a blood pregnancy test. It can provide the most accurate results, even if your hCG levels are still low.

 

When Should You Contact Your OB/GYN Or Healthcare Provider?

  • When you get a positive pregnancy test: for a prenatal checkup, ideally with a doctor from the obstetrics/gynecology department:
  • When you’re TTC (trying to conceive) but keep getting negative results: for fertility considerations (including work-up and possible treatments)

 

Where To Get Free Pregnancy Tests

  • Local health units or community centers
  • Family planning clinics
  • Adoption service agencies
  • Campus health services

 

At-Home Pregnancy Test Kits To Consider

  • Clearblue Rapid Detection Pregnancy Test
  • First Response Pregnancy Test

 

 

 

References

(1) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8087939/

(2) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9699690/

(3) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8971111/

(4) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8156690/

(5) https://flo.health/tools/hcg-calculator

(6) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1650088/

(7) https://health.clevelandclinic.org/false-positive-pregnancy-test

(8) https://my.clevelandclinic.org/health/drugs/18559-human-chorionic-gonadotropinhcg-injection

(9) https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/home-pregnancy-tests/art-20047940

(10) https://www.healthdirect.gov.au/periods-while-breastfeeding

(11) https://www.mayoclinic.org/diseases-conditions/amenorrhea/symptoms-causes/syc-20369299

(12) https://www.spirehealthcare.com/health-hub/specialties/womens-health/what-causes-cramps-no-period-and-white-discharge/

(13) https://nortonhealthcare.com/news/cramps-but-no-period/

 

 

 

– Motherhood Community is reader supported. When you buy through links on our site we may earn an affiliate commission. Learn More