Parentpedia

What Experts Say^*

Are you pregnant or not? A home pregnancy test can sometimes mean a whole lot of baggage packed into a flimsy cardboard box. You're likely feeling a messy mix of trepidation, excitement, hope, and fear as you wait for the results. And once you get them, can you trust them? Find out about pregnancy tests to help you lighten your load.

How They Work

All home pregnancy tests test for the presence of hCG, or human Chorionic Gonadotropin, in a woman's urine. The fertilized egg begins to produce this hormone once it's implanted in the uterine wall, which usually happens...

Are you pregnant or not? A home pregnancy test can sometimes mean a whole lot of baggage packed into a flimsy cardboard box. You're likely feeling a messy mix of trepidation, excitement, hope, and fear as you wait for the results. And once you get them, can you trust them? Find out about pregnancy tests to help you lighten your load.

How They Work

All home pregnancy tests test for the presence of hCG, or human Chorionic Gonadotropin, in a woman's urine. The fertilized egg begins to produce this hormone once it's implanted in the uterine wall, which usually happens 11 to 12 days post-conception.

Most tests recommend you use your first morning urine because the hormone, if present, will be most concentrated if you've held your urine for at least four hours.

While all pregnancy tests work the same way, not all are created equal.

"Some tests are more sensitive than others, meaning they can detect lower levels of hCG so they can be used sooner," says Suzanne Schlosberg, author of "The Essential Fertility Log: An Organizer and Record-Keeper to Help You Get Pregnant."

This is why your may get a positive test using one brand and a negative test using another.

Are They Accurate?

False negatives are pretty common especially if the woman is testing early or not using a very sensitive test. During the first four to six weeks of pregnancy, hCG doubles every 48-72 hours, so if you think you might be pregnant but your first test is negative, you should try again in a day or two.

False positives are less common and a positive pregnancy test followed by a period may be a very early miscarriage. If you have a positive test and then have any bleeding, check with your doctor and ask for an ultrasound. It's also possible – although unusual – to have spotting in pregnancy that can mimic a period.

What Do You Say?

Add a Question or Write an Answer

Helpful Resources

Tell Your Story