How Soon Do Pregnancy Tests Work?

If you suspect you might be pregnant, there's no question you're eager to take a pregnancy test to be certain. But taking a test too early can produce inaccurate results and leave you questioning the reliability of the outcome.

How They Work

Home pregnancy tests detect human chorionic gonadotropin (hCG) in the urine, a hormone the body produces when a fertilized egg implants in the uterus, about six days after fertilization.

Urine and Blood Tests

Urine tests performed by the doctor work the same way as home tests but health professionals are also able to perform a blood test.

hCG Levels

Many home tests claim to offer accurate results just one day after a missed period but the longer you wait, the higher hCG levels will rise and give you a more accurate result.

Considerations

According to the National Women's Health Information Center, in up to 10 percent of women implantation will not occur until after the missed period so a test immediately after the expected period may be inaccurate.

Ideal Time

The best time to take a pregnancy test is a week after the missed period to get the most accurate results.

References

• BabyCenter
• The National Women's Health Information Center