You've taken a home pregnancy test, and the result is positive. But is there any chance that it could be wrong?

By Elena Donovan Mauer
February 03, 2015
woman holding pregnancy test
Credit: iStockphoto

Home pregnancy tests are pretty reliable -- in fact, most of them can detect a pregnancy with 97 percent accuracy as early as the day after you miss your menstrual period. The tests work by indicating whether or not there's a pregnancy hormone called human chorionic gonadotropin (hCG) in your urine. If you've got a measurable level of hCG, congratulations! You're pregnant -- with these few, rare exceptions.

Chemical pregnancy

The most common explanation for a "false positive" is that you really were pregnant when you took the test. "Some women can get a positive pregnancy test and then three days after their period is due, they have a really heavy period," says Lanalee Araba Sam, M.D., an ob-gyn in Fort Lauderdale. "Really what they've had is an early miscarriage called a chemical pregnancy, and a lot of people call that a false positive. They don't recognize it as a positive pregnancy test that ultimately results in miscarriage." Dr. Sam explains that as many as 25 to 40 percent of pregnancies may end as an early often-undetected miscarriage. Some women don't even know they're pregnant in the first place.

Once you get your positive pregnancy test result, call your doctor and make an appointment. It may be many weeks away, and it can be stressful to wait for acknowledgment that everything's okay with your pregnancy. But, Dr. Sam explains, an ultrasound can't help your doctor see the gestational sac until about 6 weeks, and can't detect a fetus with a heartbeat until around 6 or 7 weeks. Once you see that heartbeat, your chance of miscarriage plummets to less than 5 percent.

In the meantime, look out for heavy bleeding or intense cramping, and call your doctor right away if you experience either of them.

Recent miscarriage

If you've had a miscarriage, hCG can stay in your bloodstream for several weeks afterward, or until your period returns, says Dr. Sam.

Pregnancy test errors

Check your pregnancy test kit to make sure it hasn't expired, and follow the instructions carefully. Making a mistake can affect the reliability of the test results.


As part of infertility treatments, some women receive hCG injections to cause them to ovulate. If you're one of them, your doctor will advise you on how to accurately test for pregnancy.

Other medications, such as methadone, could also interfere with pregnancy test accuracy, says Sean Daneshmand, M.D., an ob-gyn based in San Diego and founder of the nonprofit organization Miracle Babies.

Rare tumors

In some instances, tumors in the body can produce hCG. This is the case for certain ovarian germ cell tumors and gestational trophoblastic disease, a rare condition in which the cells that normally form the placenta develop tumors instead, says Dr. Daneshmand.

The bottom line is this: If you had a positive pregnancy test, it's 97 percent certain that you're pregnant.

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Comments (2)

August 10, 2019
J'essaie de tomber enceinte depuis 6 ans que je suis mariée. Mon mari et moi avons consulté un spécialiste de la fertilité. Nous avons fait de notre mieux mais pas de chance. Mon mari a un nombre de spermatozoïdes qui va et vient, le médecin lui a recommandé de prendre le supplément Continuez qu'il fait pendant 3 ans sans changement dans la situation. Je suis tellement confus que j'ai contacté cette puissante femme spirituelle conseillée par mon ami, alors je l'ai contactée et je lui ai tout raconté sur mon problème, alors elle a accepté de m'aider, elle a prié pour moi et elle m'a envoyé un médicament à base de plantes indigène, que j'utilise, elle m'a dit de rencontrer mon mari .. Au bout de 2 semaines, j'ai utilisé le médicament qu'elle m'a envoyé; j'étais inquiète, j'ai commencé à avoir des nausées matinales et des changements hormonaux. Je me suis immédiatement rendu chez mon médecin et cela m'a confirmé que j'étais enceinte. Tout cela, grâce à la langue maternelle hindoue iya Hindi pour son aide, ainsi qu'à ma famille. Je suis maintenant une fière maman d'un petit garçon. Iya Hindi natif, elle peut certainement vous aider. ceci son adresse e-mail Appelez / écrivez-le sur le numéro Whats-app + 19145295224. Dieu te bénisse.
May 30, 2019
Thank you.