Pregnancy test

Home pregnancy tests are readily available over-the-counter at drug stores, making them a logical choice for immediate positive or negative results. They are considered accurate and reliable and can be taken from the first day of your missed period. Extremely sensitive tests can detect pregnancy even before a period is missed. NewYork-Presbyterian offers pregnancy testing at convenient locations throughout the metropolitan area.

What is a Pregnancy Test?

What is a Pregnancy Test?

Pregnancy tests check for a hormone called human chorionic gonadotropin (hCG). Pregnancy begins when hCG is produced after a fertilized egg attaches itself to the uterus. If you suspect you are pregnant, start by taking an over-the-counter pregnancy test at home.

Early pregnancy detection can help you make lifestyle changes to protect the health of a fetus, such as quitting smoking or avoiding alcohol. Pay close attention to the directions for at-home pregnancy tests, as incorrect use can result in false results.

Though at-home pregnancy tests are convenient, a blood test will ultimately determine the amount of hormone in the blood. NewYork-Presbyterian offers same-day lab results for routine lab tests at clinics throughout the metropolitan area

How Accurate are Pregnancy Tests?


Home pregnancy tests have a 99% accuracy rate, though blood tests are considered the gold-standard of pregnancy tests. The accuracy rate of an at-home pregnancy test depends on how soon after a missed period the test is taken. The amount of pregnancy hormone increases each day—waiting a few extra days will increase the presence of hCG, making it easier to be detected in your urine by a test. You can get a false negative from a home pregnancy test if it’s taken too soon for the hormone hCG to be detected. 

It’s suggested that you test in the morning when the hormone is typically most concentrated in your urine. If you receive a negative result but still believe you are pregnant, make an appointment with your healthcare provider to help determine the result.

Fertility drugs that contain the hormone hCG could alter the results of a pregnancy test.  However, most medications including birth control pills and antibiotics do not affect the accuracy of a pregnancy test. In rare instances, false positive results can happen. 

When Can Pregnancy Be Detected with a Test?


To most accurately detect pregnancy with a home pregnancy test it is best to wait at least a week after your missed period. However, some tests are sensitive enough to detect pregnancy after the first missed day of your period. Some factors might affect the accuracy of a pregnancy test, including:

  • Testing first thing in the morning is recommended, as the hormone hCG is more concentrated at that time. Additionally, taking certain tests that can’t detect a smaller amount of the hormone hCG may affect accuracy. Check the product package for information regarding the level of hormone needed to detect pregnancy.
  • If you test for pregnancy before the embryo has attached to the uterus, the hormone hCG has not had the opportunity to be produced
  • Using an expired test could affect the accuracy of your result

Where to Get a Test

Where to Get a Test

At-home pregnancy urine tests are available at most drug stores and chain department stores with a health care section.

Blood tests for pregnancy must be administered by a healthcare professional. You can receive all your obstetric and gynecologic services in one place at NewYork-Presbyterian’s state-of-the-art medical facilities. Our expert obstetrician-gynecologists are available for you through every life stage, from child and adolescent needs to menopause and beyond.

Types of Pregnancy Tests


There are two main types of pregnancy tests available: at-home urine pregnancy tests and blood tests.

Pregnancy urine tests

These pregnancy tests work by measuring the amount of the hormone hCG present in your urine. This is done by either placing a few drops of urine on a chemical strip or holding the strip in the urine stream. Positive results are possible even if your period is only one day late. However, professionals suggest waiting until your period is at least one week late to make sure a false negative is not registered. False-positive pregnancy tests are unusual.

Though at-home pregnancy tests are considered 99% accurate, some factors that could affect their accuracy are:

  • The time of day a test is taken can affect the results of your pregnancy test. Morning urine is considered the most concentrated, meaning it contains the most amount of hCG hormone, which is produced during pregnancy.
  • In rare cases, the hormone hCG is produced but the embryo cannot be sustained in the uterus. This is known as a biochemical pregnancy.
  • If you've had an ectopic pregnancy before and suspect that you’re pregnant, see a doctor right away. In an ectopic pregnancy, the embryo will attach itself outside the uterus and will cause a positive pregnancy test result since the hormone hCG is still being produced.

Blood pregnancy tests

Pregnancy blood tests are considered 100% accurate. There are two main blood tests, each used to measure the hormone hCG.

  • The quantitative pregnancy blood test measures the exact amount of hCG in the blood, allowing the doctor to determine where you are in your pregnancy
  • The qualitative pregnancy blood test checks for the presence of hCG, but not the exact levels. This test cannot estimate how far along the pregnancy has progressed.

Blood tests are the most precise pregnancy tests available and can help confirm the results of a urine test. Blood tests, or clinical pregnancy tests, are available at NewYork-Presbyterian throughout the New York City and Westchester area.

What Steps Should I Take If I Get a Positive Pregnancy Test?

If You Get a Positive Test

Once your pregnancy is confirmed by a blood test, your doctor will set up an appointment for an exam. Early prenatal care is essential for the health and safety of both you and your unborn fetus. 

  • Your obstetrician will suggest taking prenatal vitamins to help you get the nutrients needed for a healthy pregnancy
  • Your doctor will also make suggestions for following healthier eating habits
  • Your healthcare team will introduce exercises designed to improve your overall health and help ease pregnancy symptoms
Get Care

Trust NewYork-Presbyterian for your Pregnancy Needs

NewYork-Presbyterian can help address all of your pregnancy-related questions and concerns. Our team of top-quality obstetric and maternity professionals is here to guide and support you through every step of your journey.