Traditionally, testing for pregnancy can be done at home with a store-bought urine test or at a doctor’s office with a blood test. Both of these tests detect the presence of human chorionic gonadotropin (HCG), a hormone your body only produces during pregnancy. If there is any HCG in your system, it means that an embryo has implanted itself in your uterus, and you are pregnant. Testing too early can result in a false negative, if HCG levels are not high enough to be detectable in your urine. But it’s essentially impossible get a false positive, and even the faintest line on a urine test indicates that you are likely pregnant. DIY pregnancy tests are said to detect HCG by creating a chemical reaction with the hormone in your urine. Essentially, most of these tests are done by mixing your pee with a substance found in your kitchen, medicine cabinet, or broom closet, and look for a reaction that would supposedly only happen if HCG were present. But do they work? We turned to the experts to find out what they think about these DIY pregnancy tests, and whether or not they can be trusted.

How Do Traditional Pregnancy Tests Work?

Store-bought pregnancy tests come in a pack of test sticks. To use one, prepare a urine sample in a clean container. Unwrap a test stick and dip it into the urine about 15 seconds. You can also direct your urine over the test. Then lay the test flat and wait about three minutes to read the result. You are looking for two lines in the test window. One of these lines is the control line. The control line should always appear. If it doesn’t, something was wrong with the test and you need to repeat it with a new strip. If you see only the control line, your test result is negative. This means that you might not be pregnant. It’s possible that HCG levels are not yet concentrated enough in you urine to be detected. If you still don’t get your period after a day or more, take another test. If you see the control line along with another line, your result is positive. It doesn’t matter how light or dark the second line is. This line indicates the presence of HCG in your system, and that means that you are most likely pregnant. Your healthcare provider will confirm this with a blood test or ultrasound. Blood pregnancy tests can detect pregnancy sooner and more accurately than urine tests. These can be done in a doctor’s office or lab. Using a blood sample, these screenings measure the amount of HCG, rather than just its presence. If you have a history of miscarriages, your provider may want to do a series of blood pregnancy tests to confirm that your HCG is rising at a healthy rate.

Can You DIY a Pregnancy Test?

Here are a few of the at-home pregnancy tests that have been circulating online, along with what experts have to say about their safety and efficacy.

The Bleach Pregnancy Test

For this test, you’re supposed to mix equal parts bleach and urine in a clean container. Supposedly, if it foams after a few minutes you could be pregnant. “I don’t recommend this test because mixing bleach and urine creates toxic fumes,” says Kim Langdon, MD, an Ohio-based OB/GYN with over 20 years of experience.

Dandelion Leaves Pregnancy Test

Try collecting some dandelion leaves and pouring your urine over them. If red blisters appear on the leaves, this is supposed to indicate the presence of HCG. Some claim that this is an ancient method of detecting pregnancy, but there is really no evidence to back it up, says Sam Rahman, a board-certified OB/GYN and Clinical Assistant Professor of OB/GYN at Northwestern Feinberg School of Medicine in Chicago.

The Jar Pregnancy Test

In this test, all you do is pee into a clear container and let it sit. A layer of froth that appears at the top after 24 hours is supposed to mean you’re pregnant. But this can also happen if you are dehydrated or have an infection, so it’s not a reliable method.

The Sugar Pregnancy Test

Mix your urine with one tablespoon of sugar and watch to see whether it clumps or dissolves. Clumps of sugar are said to indicate a pregnancy. However, as anyone who bakes knows, sugar often clumps inside liquid, so this is likely not very accurate.

The Toothpaste Pregnancy Test

Combining urine with white toothpaste is said to make it foam up or turn blue if there is HCG present. But there are so many different types of toothpaste with so many different ingredients that it would be hard to say whether a change in the paste’s color or texture really means you’re pregnant.

The Vinegar Pregnancy Test

Mix half a cup of urine with a cup of white vinegar and wait a few hours to see what happens. If the mixture changes color, you could be pregnant. “This hasn’t been confirmed by any kind of scientific evidence,” notes Dr. Rahman.

If You Think You’re Pregnant

If you think you’re pregnant, there’s no harm in trying a DIY test, but you will want to take a store-bought urine test before you call your healthcare provider. “We are going to want you to have an actual positive result on a drug store test before we see you,” says Dr. Langdon. “Then we will do an ultrasound which will confirm that you’re pregnant and whether the pregnancy is progressing well.”

A Word From Verywell

DIY pregnancy tests are not a reliable way to test for pregnancy, though they might be fun and generally won’t hurt. The bleach test can be dangerous, however, because urine and bleach mixed create toxic fumes. You probably want to skip this one if you think you could be pregnant. Remember that there is no evidence that DIY pregnancy tests actually work so don’t make any plans based on their results. As always, if you have any questions or concerns, please reach out to your OB/GYN or healthcare provider.