- There are two main types of pregnancy tests: urine and blood tests.
- Take a home urine test after your next missed period — anywhere from 14 to 18 days after conception.
- Blood tests are more sensitive and can tell you if you're pregnant 6 to 14 days after conception.
You have two options when it comes time to see if you have a baby on board.
The most common is an at-home urine pregnancy test, available over the counter, though you can take a urine pregnancy test at a medical clinic. Another option is a blood test performed at a medical clinic.
"Both tests check for a hormone called human chorionic gonadotropin, or hCG," says Crystal Newby, MD, of Kansas City Ob-Gyn. "This hormone is produced after a fertilized egg attaches to the wall of your uterus."
The egg typically attaches 6 days after fertilization, at which point, hCG levels in your blood and urine will increase for the next 6 to 10 weeks. Once hCG levels are high enough, you can expect an accurate reading, but not before then.
When should you take a blood pregnancy test?
Depending on a woman's cycle, a blood test can detect pregnancy between 6 and 14 days after conception.
Blood tests for pregnancy are more sensitive to hCG than home pregnancy tests. They can detect this hormone in low quantities and tell you if you're pregnant sooner than a home test.
While blood tests can provide results sooner than home pregnancy tests, they are usually more expensive and take longer to provide results because the blood must be sent to a lab for analysis.
If the lab is in-house then it will take a few hours. But if the lab is at a different location, it could take several days to learn the results.
When should you take a home pregnancy test?
Most home pregnancy tests advise you to take the test after you miss your next period. If you have a standard 28-day cycle, you'll be most fertile two to three weeks before your period.
So if you get pregnant during that fertility window, you'll need to wait at least 14 to 18 days after conception to take a home pregnancy test.
If you get a negative result and suspect you're pregnant, check the instructions on the box. Home pregnancy tests typically recommend retaking the test 5 to 7 days later, when the hCG levels in your body will be higher.
This type of result is called a "false negative." Sometimes you can receive a false negative result if you take a pregnancy test too soon when your hCG levels are too low for the test to detect them accurately.
Moreover, recent miscarriages, fertility drugs, and rare hCG secreting tumors can interfere with the results of at-home urine tests. If you receive conflicting results after taking a home pregnancy test multiple times, doctors recommend a blood test.
How accurate are pregnancy tests?
Blood pregnancy tests are considered by doctors to be 99% accurate. Quantitative blood tests (also called beta hCG tests) are the most accurate blood tests and can help doctors tell the exact age of the fetus and play a role in detecting any abnormalities.
If you follow directions, home pregnancy tests are an estimated 97% to 99% accurate. If you perform a urine pregnancy test in a lab setting, like at your doctor's office, the accuracy will be closer to 99%. It's important to make sure that you check the expiration date on your home test, as it can affect the accuracy of the results.
After taking either a blood or urine test, it's important to confirm the pregnancy with an early ultrasound.
Insider's takeaway
Home pregnancy tests can provide results faster and be more convenient than a blood test. But you'll probably have to wait longer to receive accurate results.
You can expect accurate results from a blood pregnancy test as soon as 6 to 14 days after conception. Because the test must be analyzed in a lab, it could take up to several days to get the results.
To get the most accurate reading from a home urine test, wait until your missed period. This can come anywhere between 14 to 18 days after conception. If you get a negative result, you can try taking a home test again in 5 to 7 days to see if you have higher amounts of detectable hCG in your body.
Blood tests are considered to be 99% accurate, while home pregnancy tests are around 97% to 99% accurate. Regardless, you should confirm your results by getting an ultrasound.
Denice Rackley is a freelance writer for Insider.
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For many people, the decision of when to take a pregnancy test can be a major source of anxiety. Sometimes the stress is because you want to be pregnant. Sometimes it’s because you don’t want to be.
Regardless of whether you’re hoping for a negative or a positive result, taking an early test may seem like a good way to find out if you’re pregnant right away. Unfortunately, early testing may give you a negative result, even if you are pregnant.
It's important to take the test at the right time to maximize your chance of getting an accurate reading. Learn the best time to take a pregnancy test in order to get the most
accurate result, as well as the risks associated with testing too early.
The Best Time in Your Cycle to Take a Pregnancy Test
The best time to take a pregnancy test is after your period is late. This will help you avoid false negatives. If you're not already keeping a fertility calendar, proper pregnancy test timing is a good reason to start one.
If your cycles are irregular or you don’t chart your cycles, do not take a test until you have passed the longest menstrual cycle you usually have. For example, if your cycles range from 30 to 36 days, the best time to take a test would be day 37 or later.
Something else to consider is whether you know if your period is even late. According to the FDA, out of every 100 people, between 10 and 20 will not get a positive pregnancy test result on the day they think is just after their missed period, even if they are pregnant.
Tests labeled for early pregnancy detection may be able to detect a pregnancy several days before your expected period. However, the most accurate results come after your period is late.
The time of day you take a pregnancy test does matter to a certain extent. You’re more likely to get an accurate result if you take the test in the morning. This is especially true if your period is not yet late, or if your period is only a couple days late.
At-home pregnancy tests work by detecting the hormone human chorionic gonadotropin (hCG) in your urine. Unless you get up in the night to pee often (or you drink water throughout the night), your urine is more concentrated when you first wake up. This usually means that the amount of hCG is a bit higher, and you’re more likely to get a positive result if you’re pregnant.
However, you can still take a pregnancy test in the middle of the day, or even at night. You’re just more likely to get a false negative, especially if your period isn’t that late, and especially if you’ve been drinking a lot of water and your urine is diluted.
Taking a Pregnancy Test Because of Symptoms
You may decide to take a pregnancy test because you are having
early pregnancy symptoms. But keep in mind, the same hormones that cause pregnancy-like symptoms are present every month between ovulation
and your period. Many symptoms similar to pregnancy symptoms can have other causes, like a cold, the flu, or even a few nights of poor sleep.
Early Signs of Pregnancy
- Breast tenderness
- Frequent urination
- Mild cramps (sometimes called “implantation cramps”)
- Very light spotting (sometimes called “implantation spotting”)
- Fatigue
- Sensitivity to smells
- Food cravings or aversions
- Metallic taste
- Headaches
- Mood swings
- Slight morning nausea
Depending on whether a positive pregnancy test would be good or bad news, symptoms like these may fill you with dread—or excitement. But here’s the good (or bad) news: pregnancy symptoms do not mean you are pregnant. In fact, you
can feel pregnant and not be pregnant, or not feel pregnant when you really are expecting.
How Do Pregnancy Tests Work?
Knowing how pregnancy tests work can help you understand when to take them. Pregnancy tests relay how urine reacts with a piece of paper that can detect the presence of hCG. Results are usually shown as a single or double line or a plus or minus sign.
An at-home pregnancy test can't measure the exact amount of pregnancy hormone in your urine. What it can do is detect whether a minimum amount is present.
Getting a negative pregnancy test result doesn't mean your urine doesn't contain the pregnancy hormone (hCG). It just means it doesn't contain enough to trigger a positive result.
"Early results" pregnancy tests promise results as soon as three to six days before your missed period. These tests are more sensitive than standard tests but getting accurate results that early is more difficult simply because ovulation and implantation times can vary. If you have irregular periods, it can be even more difficult to know when might be an accurate time to try an early test.
If you're having fertility treatments, be aware that this may result in a false positive pregnancy test, especially those performed early. That's because pregnancy tests may detect the remains of fertility medications like Ovidrel, Pregnyl, or Novarel.
How Accurate Are Pregnancy Tests?
If you read the instructions carefully, most tests promise 99% accuracy on the day of your missed period—but not for early results. If you expect your period on Wednesday, Thursday would be the day of your missed period. Tests tend to be more accurate after your missed period. Likewise, first morning urine may be more concentrated and detect hCG more accurately.
Variables Affecting Accuracy
Keep in mind that the test's accuracy can depend on several variables. These include:
- When in your cycle you take the test
- The timing of ovulation
- How closely you follow the directions
- The time of day you test
Efficacy of Early Testing
If you are considering taking a test before your period is late, it is important to consider the pros and cons before you do. Not only could it be expensive to take pregnancy tests too early, but it also could give you inaccurate results. medications
Pro
Chance of getting a positive result
If positive, relieves some of the stress during the two-week wait
Useful if you need to start or stop medications or other early interventions
Allows you to begin lifestyle adjustments right away
Con
Higher chance of a false negative result
Feelings of disappointment with negative result
Expense
Not accurate with hCG trigger shots such as Ovidrel
The Best Early Test
If you still want to take an early test, despite the possible downsides, you may want to consider a test with a proven track record. According to research, the First Response Early Result (FRER) manual test is the best early pregnancy test on the market now.
The digital test, First Response Gold Digital Pregnancy Test, had previously been reported as less accurate. However, according to a 2013 FDA comparison between the two, the results show the same accuracy.
This pregnancy test has clearance from the FDA to say it can detect pregnancy hormones 6 days before your missed period. That is 5 days before your period is due. There are plenty of other early pregnancy tests on the market. Which one is right for you may depend on factors like cost, result
speed, and whether you prefer digital or paper tests.
When to Get a Blood Pregnancy Test
You might be wondering if you should also have a blood test to check if you are pregnant. Your doctor may order a test, or you may be thinking about ordering one yourself. Many labs now allow people to order and pay out of pocket for their blood work.
Before you do that, there are a few things you should know. First, there are two types of pregnancy blood tests: qualitative and quantitative.
- Qualitative tests measure whether hCG is present in your blood or urine. They pretty much give a yes or no answer as to whether you’re pregnant. Or, more accurately, whether you have enough pregnancy hormone to get a positive result. Home pregnancy tests are qualitative.
- Quantitative pregnancy tests measure the amount of pregnancy hormone in your blood. This is sometimes called a beta hCG test. These are usually done to see how a pregnancy is progressing. For example, your doctor may order two beta hCG tests a few days apart to see whether the level of hCG is increasing as expected or not. This might be important if you had trouble conceiving, have a history of early miscarriage, or an ectopic pregnancy is suspected.
Blood Test Result Timetable
Blood tests are able to detect a smaller amount of hCG and they can detect it slightly earlier than standard at-home pregnancy tests, usually nine to 12 days after conception. Blood test results are usually available the same day or within a day.
Blood tests aren't often done to detect pregnancy because they are expensive and at-home urine tests are quite accurate and sensitive. However, people who are undergoing fertility treatments may have blood tests as part of their care.
When a Blood Test Is Used
If your period is late by several days, and you’re still getting negative at-home pregnancy tests, a blood test may be recommended. While rare, it is possible to get a negative test result on an at-home test but still be pregnant. If this is your situation, call your doctor, and don’t just order a test on your own. There are other reasons besides pregnancy that your period may be late.
You don’t necessarily need a blood test to confirm a positive at-home pregnancy test. If the at-home test said you’re pregnant, you’re likely pregnant. That said, your doctor might still order one, especially if you request it.
A Word From Verywell
The best time to take a pregnancy test is the day after your expected period and in the morning hours, with your first urine of the day. However, when you're anxious to see results, it's understandable if you are tempted to test earlier.
Before you reach for that early pregnancy test, carefully consider how you'll feel if the results are negative. If a negative test doesn't bother you, and you have the cash to spend on pregnancy tests, go ahead. If a negative result is going to make your heart ache or if you’d rather not waste money on extra tests, then wait until your period is late.