How Soon Can You Take a Pregnancy Test?
Whether you are planning to get pregnant or are worried about being pregnant, it is often difficult to wait to take a pregnancy test. You want to know the outcome as soon as possible. Yet, if you take the test too soon, the results may not be accurate.
The typical recommendation is to wait until after a missed period. However, you may not want to wait that long. Before you rush to the store and purchase a pregnancy test, you should understand how these tests work, what they measure, and how to determine the best time to take the test.
How Do Pregnancy Tests Work?
Most women know how to use a modern over-the-counter pregnancy test. Whether you purchase a name brand test or a generic version, the instructions are typically the same.
You urinate onto the stick for a specific amount of time and then wait impatiently for the results to appear. However, there is much more to these tests.
Pregnancy tests measure a hormone called human chorionic gonadotropin (hCG). The hCG hormone is produced by the developing placenta, which then releases the hormone into the bloodstream. Trace amounts of this hormone may also be detected in your urine, allowing the detection of pregnancy from either your blood or urine.
While a blood test can offer a more accurate result, these tests are only done at the doctor’s office or hospital. As higher hCG levels are found in the blood, a blood test may also be performed earlier.
Unfortunately, you may need to wait several days to hear back from your doctor, which can eliminate the benefit of early detection.
When you buy a home pregnancy test, you are checking your urine for hCG levels. While the hormone is produced by the placenta, non-pregnant women still have small amounts of hCG in their system. Several days after fertilization, these hCG levels should start to increase.
Most doctors agree that it often takes about two weeks after conception for hCG levels in the urine to be high enough for detection with a urine test. If you wait for the recommended amount of time, the home pregnancy test should offer an accurate result.
Waiting 14 days to take a pregnancy test after your last missed period may be tough to handle. If you take a pregnancy test on the first day of your missed period or earlier, do not be surprised if you get a negative result.
You simply may not have enough hCG in your urine for detection. Wait another week before taking the test again.
Your hCG Levels Rapidly Increase When Pregnant
As mentioned, the placenta is responsible for producing and releasing the hCG hormone that is detected in your blood or urine. Low levels of the hormone can be found with a blood test about seven days after you get pregnant. However, these levels may increase by up to 300% within several weeks.
The primary reason that doctors recommend waiting at least one week after a missed period is to avoid a false negative result. When you take the test too early, you may not have enough hCG for detection but you may still be pregnant.
Non-pregnant women often have hCG blood levels below 10 µ/L. Within one to two weeks after fertilization, hCG levels in the blood may increase to 25 µ/L.
While this may seem to be a big increase, women that are four weeks pregnant may have hCG levels as high as 750 µ/L. A week later, these numbers may increase to 7,000 µ/L.
The difference in hCG levels between a non-pregnant woman and a woman who is two weeks pregnant is very small. However, after your missed period, the levels begin to increase quickly and then peak around the end of your first trimester. After about 16 weeks, the hCG levels should begin to decrease.
When Should You Take a Pregnancy Test?
If you decide to take a home pregnancy test, it is best to wait until your hCG levels are high enough for detection in your urine. For most women, the hCG levels may not be high enough until two weeks after the fertilization of the egg.
While the typical recommendation is to wait one week after your last missed period, you may technically take the test 14 days past ovulation. The problem with using ovulation as a timeframe is that many women do not know when they are ovulating.
The average menstrual cycle lasts 28 to 32 days. Ovulation typically begins about 10 to 19 days into the cycle or about 12 to 14 days before your next period.
You are most fertile on the day of ovulation. That day is your best chance of getting pregnant. However, your fertile window starts about five days before ovulation. These are the five days out of the month when you can get pregnant and you need to wait at least 14 days later before hCG levels are high enough for the urine test.
If ovulation typically occurs 12 to 14 days before your next period, shouldn’t you be able to test on the first day of your missed period? Yes. You can test on the first day of your missed period but the hCG levels may still be too low to guarantee an accurate result.
Assuming that you have a normal menstrual cycle, your missed period may indicate that you are about two weeks pregnant. Waiting an extra two weeks beyond your missed period gives the placenta more time to develop and produce more hCG, decreasing the risk of a false negative pregnancy test.
Tips for Avoiding False Positive Pregnancy Tests
Home pregnancy tests are not always accurate. A false positive is when the test determines that you are pregnant even when you are not pregnant. A false negative is a negative result when you are pregnant.
Waiting two full weeks after your missed period to take a pregnancy test limits the chances of an inaccurate reading. However, it is still possible to get a false positive or false negative result.
The most common causes of a false positive include a chemical pregnancy, infertility treatments, perimenopause, and luteinizing hormone (LH) peaks.
A chemical pregnancy is a name given to an early pregnancy that results in miscarriage. When a chemical pregnancy occurs, the hCG levels should return to normal after the miscarriage. However, if you take a pregnancy test too early, you may detect the chemical pregnancy.
Perimenopause causes some women to experience higher levels of hCG even when they are not pregnant. The increase in hCG levels may result in a false positive.
Women who receive certain fertility injections to stimulate their ovulation as part of a fertility treatment may get a false positive result. This is more likely to occur when the test is taken 10 days or less from the time of the last fertility injection.
LH peaks are another possible cause of a false positive pregnancy test. Luteinizing hormone is a hormone that is produced by the pituitary gland at low levels throughout your entire menstrual cycle. However, LH secretion increases to higher levels about 24 to 36 hours before ovulation.
The hCG hormone can be released by the pituitary gland at the same time as your LH peak. When this occurs, there is a slight chance that you may get a false positive.
How to Reduce Your Risk of False Negative Results
The most common cause of a false negative result is testing too early. All women are different. Early in your pregnancy, you may not produce enough of the hCG hormone for detection.
Other potential causes of false negative results include diluted urine or not testing your urine instantly.
When you drink too much liquid before taking the pregnancy test, your urine may be too diluted to accurately test your hCG levels. Instead of chugging water before taking the test, follow your normal routine and avoid drinking excess liquids.
Some women may choose to urinate in a container or cup and then use the collected urine with the home pregnancy test later. Allowing collected urine to set for more than 30 minutes can often result in a false negative.
Another potential cause of a false negative is not using a sensitive pregnancy test when taking the test before the recommended time. If you take your test early, make sure that you purchase a sensitive pregnancy test. These tests are often labeled as early detection tests.
What Should You Look for in a Pregnancy Test?
Almost every convenience store, gas station, and grocery sells pregnancy tests. You will often find the same two or three brands in every store. However, there are also dozens of different options available online.
If you cannot deal with the excitement or anxiety of waiting to find out, you should use a sensitive pregnancy test for early detection. If you wait for the recommended two weeks after your last missed period, almost any pregnancy test that you buy should offer 98% or greater accuracy.
In the end, the most important thing you can do is wait for your hCG levels to increase. Wait at least one week after your missed period. Whatever results you get, you should consider testing again several days later to verify the earlier test.
Regardless of whether you are hoping for or against pregnancy, good luck with your test.