There are a few things in life that should remain a mystery, but the results of a pregnancy test is not one of them. If you’re relying on that little stick to tell you whether or not you need to start decorating the nursery, you need it to be accurate. We’ve all heard of false negatives happening, but what about getting a false positive on a pregnancy test? To save you the annoyance of peeing on a stick five times to ensure you’re getting an accurate result, I spoke to Dr. Jessica Brown, who specializes in infertility and gynecology at Madison Women’s Health and Fertility, about this common question many women have.

According to Brown, at home pregnancy tests are pretty reliable. She said receiving a false positive on a urine sample test is very unlikely, though there are a few cases where it may be more probable to happen.

“False negatives are definitely more common,” Brown says, adding the results of your test may vary depending on the stage of your pregnancy. If you’re more than 10 to 14 days along (after conception), the time when the pregnancy hormone hCG becomes traceable in your urine, the chances of getting a false positive are slim. At home pregnancy tests are thought to be 97 percent accurate- so as long as you’re within the time frame and follow the test instructions, the results should be spot on.

Another situation that is less likely to happen, but is still possible, is getting a false positive while taking fertility treatments. Brown explains that fertility treatments use hCG, creating the potential for a false positive on an at home test.

Even less likely to happen is the condition known as choriocarcinoma, a very rare form of cancer than can occur during a or after a pregnancy. A pregnancy test will appear positive with this disease, because your body is producing hCG, even though there may or may not be a baby. Brown says this scenario is rare, but something to be aware of.

Though the chances of a false positive are small, it never hurts to err on the side of caution. If two little lines appear on your test or you are experiencing any pregnancy symptoms, Brown says it’s best to contact your healthcare provider. After all, you don’t want to start Pinterest planning a nursery if you don’t have to.