A pregnancy test detects a hormone called HCG (human chorionic gonadotropin). A woman’s placenta makes this hormone after a fetus has developed in her uterus. HCG is present in her blood and urine during pregnancy and not during any other time, which is why tests that detect it are the most accurate tests known for determining pregnancy. If you suspect you may be pregnant, choosing between a blood vs urine pregnancy test may be a tough choice.
Blood and urine tests are both considered accurate, but each has differences and limitations in terms of the procedure and the time during which the test is applicable. Often, you can conduct a simple OTC urine test at home and confirm it with a blood test. However, you may wonder how accurate these tests are, how they are performed, and which you should rely on.
When Should I Get a Pregnancy Test?
You may notice symptoms that make you wonder if you should administer a pregnancy test. Your doctor may order one if they notice multiple signs during a routine checkup and after reviewing your sexual history. While symptoms of pregnancy can vary between individuals and at different times, common symptoms of being pregnant include:
- Urinating frequently
- Feeling nauseated and vomiting often
- Feeling more fatigued than usual
- Having breasts that feel swollen and tender to the touch
- Being bloated and not being able to find relief
- Missing your period
If you miss your period, which can occur around 2-3 weeks after conception, you can purchase an at-home pregnancy kit that tests your urine for HCG. If you have other symptoms and suspect a pregnancy earlier than that, a blood test can give you accurate results much earlier. This time difference is one of the major advantages of the blood test, but the urine test has convenience, cheapness, and speed on its side, which makes it much more common.
Urine Test: Procedure and Accuracy
Urine tests consist of a dipstick that comes in a home pregnancy kit. They cost very little, and you can buy them over the counter and are easy to perform by yourself or at a clinic if you prefer.
There are two ways to perform the urine test. One is to urinate into a small cup so that you can either dip the stick into it or use an eyedropper to place a few drops on the testing strip. The other method is trickier but doesn’t require disposable containers and involves urinating directly onto the stick. This is risky since urine needs to contact the strip for 5-10 seconds to ensure accurate results.
A test is complete when the strip displayed on the dipstick changes. Some change color and others display a symbol, either a “plus” or a “minus.” A “plus” means that the stick detected HCG and that the person is most likely pregnant (to make things easier, many tests now simply say “pregnant” or “not pregnant”).
A urine test is about 97% accurate. As mentioned, it can be performed a few weeks after conception. However, when done incorrectly or prematurely, the test can give a false result. It is far more common to receive a false negative than a false positive. In other words, a “plus” or “positive” pregnant result is almost always accurate, even on home kits. However, a “minus” or “negative” result, particularly when the user still has many symptoms of pregnancy, could be an incorrect result.
If this happens, you might wait a week and redo the test with a new kit or go in for a blood test. Schedule an appointment with your doctor to discuss your symptoms and results.
Blood Test: Procedure and Accuracy
The biggest disadvantage of a blood test compared to a urine test is that a healthcare provider must perform it. This not only requires an appointment but also the patient to disclose their sexual history, which can be uncomfortable. Many opt for a urine test not only for convenience but also for privacy.
However, if you suspect a false negative on a home pregnancy test, want the most accurate results, or want to determine if you’re pregnant much earlier, a blood test has an advantage over a urine test. These tests can detect even less HCG and can therefore be performed sooner than a urine test at around 7-12 days after conception (you don’t have to wait until you miss your period).
Blood tests are 99% accurate in ruling out pregnancy. They are often used to confirm the results of at-home kits. However, they can be performed at most times during the pregnancy to receive the most accurate results.
What if different tests give different answers?
If you perform multiple urine tests and receive different results, talk with your healthcare provider to get a blood test to confirm the correct result, as they are the most accurate test readily available.
Book An Appointment
Both urine and blood pregnancy tests measure how much pregnancy hormone, hCG, you have in your body after the fertilized egg binds to the wall of your uterus. This process typically happens about six days after fertilization of the egg. As your pregnancy progresses, you have more hCG in your body and pregnancy tests become more reliable. Our pregnancy blood test uses technology to detect adequate hCG levels about six to eight days after ovulation for highly accurate results. Reach out to your Dr or book an appointment now.
*This content is for informational purposes only and is not meant to replace consulting with a healthcare professional. Please consult with your primary care physician or healthcare provider before engaging in any services offered by Speedy Sticks.