Even though home pregnancy tests are often sold as a safe and reliable method, there is always the possibility that the results are not correct. For example, it is possible to get a false positive; that is, that the test shows that you are pregnant even though you really are not.
In pregnancy tests, false positives are less common than false negatives, which happens when a pregnancy test indicates that you are not pregnant when you really are.
Thus, if your test says that you are pregnant but you have doubts about the results, take a look at the following list where we show you 9 reasons why false positives can occur in pregnancy tests .
How do home pregnancy tests work?
In most cases, home pregnancy tests work by analyzing urine in order to detect a hormone present in pregnancy called human chorionic gonadotropin (hCG), which increases rapidly after an egg is fertilized.
If the test detects hCG in urine, the result will be positive. That is, you are pregnant. If it does not detect hCG, the result will be negative: you are not pregnant.
Most OTC pregnancy tests claim to be 99% effective; however there are some reasons that can make them less accurate and give an incorrect result.
Why can you get a false positive for pregnancy
1. You took the test too early
Although it may be tempting to take it the moment you suspect pregnancy, it is best to wait until a week after your first missed period.
We know that it feels like forever and that the wait can be overwhelming. However, tests are less certain when taken before the indicated time, which means that you are more likely to get an incorrect result.
2. You may have had a chemical pregnancy
Chemical pregnancies occur when a fertilized egg cannot implant or grow. Pregnancy is lost very early, and most women do not even realize it happened. However, it can cause the body to produce hCG, a hormone that could be detected in a pregnancy test and thus cause a false positive.
Chemical pregnancies are common and often happen for no reason, but they are one of the most important reasons why it's worth waiting at least a week after your missed period to take a pregnancy test and avoid having a false positive test. of pregnancy .
3. You have had an ectopic pregnancy
Ectopic pregnancy occurs when a fertilized egg implants outside of the uterus. It can be one of the fallopian tubes, the cervix, the abdomen, or the ovaries.
These pregnancies are not viable because an egg cannot survive or grow outside of the uterus. However, in the beginning it can promote hCG production and thus give an incorrect result.
If you have an ectopic pregnancy, some of the symptoms may be: severe abdominal or pelvic pain, spotting or bleeding, dizziness or fainting, or pressure in the rectum. If you notice any of these symptoms, seek medical help as soon as possible: Ectopic pregnancies are medical emergencies and can harm your reproductive system if not treated in time.
4. You may have suffered a miscarriage
HCG can be detected in the blood for up to 6 weeks after losing the pregnancy. Likewise, if you try to conceive again shortly after a miscarriage, the test may be positive since it detected hCG from your previous pregnancy.
5. The test showed an evaporation line
Some pregnancy tests use two lines to show a positive result (and only one line to show a negative result). The lines are usually blue or pink, but it is normal for the second line to be dimmer.
Sometimes a weak second line can mean that you are pregnant. But it can also just be an evaporation line, which forms after the urine has completely evaporated, especially if the line is totally colorless. That is why it is important to follow the instructions to the letter to avoid any kind of confusion.
Some digital tests use readings with displays showing "pregnant" or "not pregnant" instead of lines, making them a safer method to avoid confusion.
7. You are taking fertility drugs
If you have fertility treatments, your doctor may prescribe an injection of synthetic hCG. These injections cause follicles in the ovaries to release an egg, but they can also cause an over-the-counter pregnancy test to be false positive.
This is especially likely if the test is done too early. Once again, we recommend that you wait long enough to take the pregnancy test.
8. You are taking other medicines
Other medications that can affect your hormone levels and cause a pregnancy test to be positive by mistake include the following:
- Anti-anxiety medications, such as diazepam or alprazolam.
- Antipsychotics, such as clozapine or chlorpromazine
- Anticonvulsants.
- Medicines for Parkinson's disease, including bromocriptine.
- Diuretics, such as furosemide.
- Methadone (dolofin).
If you take any of these medications and are trying to get pregnant, it is recommended that you speak with your doctor. It can help you determine the best steps for your future baby to be born healthy.
9. You have a medical condition
In addition to certain medications, some medical conditions can affect your hormone levels as well and alter your pregnancy test, such as the following:
- Urinary tract infections
- Ovarian cysts
- Kidney disease
- In rare cases, ovarian cancer or pituitary problems.
What to do after you test positive for pregnancy
Whether you think the results are accurate or not, your best option is to make an appointment with your obstetrician-gynecologist. He will evaluate you in his office (with another urinalysis or a blood test) to make sure you are pregnant. If the result is positive, your doctor can help you plan the rest of the pregnancy.
conclusion
Until you have an accurate answer, the best thing to do is take a deep breath and be patient. Getting a false positive on a pregnancy test can be very stressful, so it is best to wait patiently and be aware of our actions. After all, the definitive answer will be your trusted doctor.
References
- Tasylor, M. Am I Really Pregnant? 9 Possible Reasons for a False-Positive Test. To Greatist [Revised December 2019]
