At the first unusual symptom a sexually active woman feels, the possibility of pregnancy immediately comes to mind. That’s why the first thing usually done is reaching for the traditional over-the-counter pregnancy test. It is easily accessible, both in price and because you can find it at any pharmacy. It can also give you a quicker and more discreet result if you do not want anyone else to know at the moment. But can a pregnancy test be wrong? Is it safe?

It is advisable to take a pharmacy pregnancy test with the first urine of the day. This is because HCG levels are higher in the morning. Ideally, always do the test after confirming your period is at least 5 days late.

Possible errors

The basis for urine pregnancy tests, or pharmacy tests, is the detection of the amount of HCG in the urine. This hormone, in turn, is only produced during pregnancy1. The options offered today in pharmacies and supermarkets have the lowest chance of being wrong. Manufacturers claim a sensitivity of 97 to 99.5% for accurate diagnosis. It is rare for a false positive to occur, or for a woman who is not pregnant to get a positive. However, the tests have a 0.5% chance of error. So, yes, a pregnancy test can go wrong, and there are some situations where a false positive can occur, such as:

  • Recent miscarriage, as there may still be remnants of beta HCG in the blood.
  • Use of certain medications containing hormones, usually administered for female fertility (Ovidrel, for example).

False negative

Now, for a negative pregnancy test, or what’s also known as a “false negative,” there can be several other reasons2. Among them, the most common is being too early in the pregnancy. At this stage, the level of beta HCG cannot yet be detected by the test. It can also happen that the hormone is diluted in a larger amount of water, due to excessive fluid intake. That is why it is recommended not to drink liquids for at least 4 hours before doing the test.

If you take the test and the result is a negative pharmacy pregnancy test, yet you still have a late period with symptoms, repeat the test after a week to confirm the diagnosis. If you still do not feel confident in the result, see your doctor and request a blood Beta HCG test. This will give you a more reliable result. For an accurate result, request a quantitative beta HCG3.

If you want a tip for a reliable pharmacy pregnancy test, we recommend the Famivita brand. They are more sensitive and can detect HCG levels up to 5 days before your period is late. You can learn more here.

Homemade pregnancy test

Besides the well-known pharmacy and blood tests, there are some tests that can be done at home at no cost. According to older people, the result is infallible. Here are a few of them:

Needle test

Before going to bed, pee into a small container with a lid. Then, place a small sewing needle inside and close the container for at least 8 hours. When opening, if you see that the needle has changed color, your result is positive.

Bleach test

Mix a little of your urine and bleach in a container. If the mixture turns an orange color, your result is positive; if your urine does not change color, it means your pregnancy test is negative.

Boiling test

Place your urine in a pan, preferably one you won’t use again, and heat it on the stove. If the urine bubbles like water, you are not pregnant. If it boils like milk and creates a skin around the circumference of the pan, you may be pregnant.

Obviously, these are homemade tests used since old times and there is no guarantee they will work. In fact, it is more of a joke and should not be taken seriously. If in doubt or if you suspect pregnancy, see your doctor and take a pharmacy test or a beta HCG exam to be sure.

Readers’ questions:

When can a pregnancy test be wrong?

There are some factors that can influence the error of a pregnancy test. Some of them are testing too early and before the missed period, low HCG concentration, and even poor quality of the test used. We also cannot rule out incorrect handling of the test, which can also invalidate it.

I have a late period, pregnancy symptoms, and a negative test. What could it be?

A late period is the main sign of pregnancy, especially if accompanied by other typical pregnancy symptoms. But a late period can also be the result of a hormonal imbalance, for example. Or it could be due to the use of medications that disrupt the menstrual cycle, such as the morning-after pill. In these cases, it is best to see a gynecologist and carry out tests to find the cause and treat it properly.

See also: Can I Take the Pregnancy Test Before My Period Is Late?