If you’re trying to get pregnant, the best time to take a pregnancy test is one week after you’ve missed your period. Why? Because this is really the best way to prevent a false negative result (a negative test in someone who's actually pregnant) result.
Home pregnancy tests can be used as early as the first day after your first missed period in women with regular/predictable monthly menses. If you have irregular periods, you can administer a test 14 days after intercourse, since you likely can’t pinpoint your exact time of ovulation.
Pregnancy tests detect a hormone called human chorionic gonadotropin (HCG), which is produced in early pregnancy. The production of this hormone begins slowly and increases as the pregnancy grows. Standard urine pregnancy tests will detect the HCG level when it reaches 20-50 milliunits/milliliters.
If you take a test too soon (before you've missed your period), the levels of HCG may not be high enough to detect a pregnancy and it could cause a negative result, even though you're actually pregnant.
I advise my patients to wait at least one day after you miss your period. If you wait one week after a missed period, the chance of a false negative is very low if you have a normal monthly menstrual cycle.
Brand name versus generic pregnancy tests
Home pregnancy tests, both brand name and generic, are very accurate at detecting the HCG hormone and any positive result, even a faint line, can be considered positive. HCG is only produced by a pregnancy; any positive result indicates a pregnancy.
You don’t need a serum (blood) pregnancy test to confirm pregnancy. Both urine and blood detect HCG, although the blood test is more sensitive and can detect HCG levels at much lower levels than a urine test. In certain situations, your doctor may want to perform a blood HCG test but it’s not typically needed to confirm a pregnancy.
Although most tests advertise 99% accuracy, the ability of a particular brand to detect HCG at levels less than 50 ml may vary. Some brands may be better able to detect lower levels of HCG than others. If your HCG level is more than 50 ml, which is the detection rate of most tests, even generic tests will detect a pregnancy accurately.
How to prevent a false negative result
The number one cause of a false negative test is taking the test too soon after you conceive. Also, if you don’t follow the test instructions carefully, it could affect your result.
Urine, even in women who drink large amounts of water, should still yield a positive result. But urine shouldn’t be diluted with water before taking a test. A good time to take the test is in the morning when you first wake up.
If a test is negative in a woman who suspects she’s pregnant or if she has irregular cycles, she should repeat the test in one week.
Medications and test results
Medications don’t typically interfere with results, neither causing false positive nor false negative. Only a medication containing HCG would affect the result.
When to see your doctor
Although home tests can detect a pregnancy, it gives no information as to viability. It’s important to make an appointment with your doctor to confirm your pregnancy and to detect a fetal heart rate through an ultrasound (usually at six to 10 weeks). If you have a positive pregnancy test, your obstetrician can provide information about warning signs of an abnormal or worrisome pregnancy and can advise you on when to make an appointment to confirm your pregnancy.
We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.
The best time to take a pregnancy test is a the week after a missed period. Some tests may detect pregnancy 1-2 weeks after intercourse, but the body needs time to increase its levels of HCG. Testing before a missed period can increase the risk of a false negative result.
Think you might be pregnant?
Even with the most effective birth control methods, there’s always a chance for error. After all, it takes just one sperm to fertilize the egg. Finding out whether or not that’s happened is as easy as taking an over-the-counter (OTC) pregnancy test.
OTC pregnancy tests typically test your urine for a hormone called human chorionic gonadotropin (HCG). HCG is only present if you’re pregnant. The hormone is only released if a fertilized egg attaches outside the uterus or to your uterine lining.
There are different ways to collect your urine for the test. Depending on the test you choose, you may have to:
- collect your urine in a cup and dip a testing stick into the liquid
- collect your urine in a cup and use an eyedropper to move a small amount of fluid into a special container
- place the testing stick into the area of your expected urine stream so that it will catch your urine midstream
According to Cleveland Clinic, most tests are 99 percent effective if taken after a missed period. The best part is that you can do it in the privacy of your own home. Simply open the test, follow the instructions, and wait for the recommended amount of time to view the results.
After the recommended waiting time has passed, the tests will display your results in one of the following ways:
- a change in color
- a line
- a symbol, such as plus or minus
- the words “pregnant” or “not pregnant”
You should wait to take a pregnancy test until the week after your missed period for the most accurate result.
If you don’t want to wait until you’ve missed your period, you should wait at least one to two weeks after you had sex. If you are pregnant, your body needs time to develop detectable levels of HCG. This typically takes seven to 12 days after successful implantation of an egg.
You may receive an inaccurate result if the test is taken too early in your cycle.
Here are some signs that you should take a pregnancy test.
Share on PinterestOne of the first and most reliable signs of pregnancy is a missed period.
If you don’t track your cycle closely, it might be hard to determine whether or not you’re late. Many women have a 28-day menstrual cycle. Consider taking a test if it’s been more than a month since your last period.
Keep in mind that your period can sometimes be delayed or skipped due to stress, diet, exercise, or certain medical conditions.
Also pay attention to your flow if you suspect pregnancy. It’s common to experience light bleeding or spotting in the early weeks as the egg buries deeper into the uterine lining during implantation. Take note of any difference in the color, texture, or amount of blood.
Contact your doctor if you have bleeding and a positive pregnancy test.
Share on PinterestImplantation can also produce a feeling similar to menstrual cramps. In early pregnancy, you may feel this discomfort and think your period is just around the corner, but then it never comes.
Sound familiar? Take a test. Hormone levels vary by woman and by pregnancy.
Share on PinterestAs your pregnancy produces more and more estrogen and progesterone, these hormones start to make changes in your body to support the baby’s growth.
Your breasts may feel tender and appear bigger due to increased blood flow. Your nipples might hurt and the veins might look darker under the skin.
Because many women also experience breast discomfort in the days leading up to their period, this symptom isn’t always indicative of pregnancy.
Along with cramps and sore breasts, early pregnancy can cause:
- nausea
- food aversions
- exhaustion
- frequent urination
As the weeks go on, these symptoms may get stronger before your HCG levels even out late in the first trimester. You know yourself, so pay attention to your body. Any unusual physical symptoms could prompt you to take a pregnancy test.
Share on PinterestBirth control pills, condoms, and other types of contraceptive devices don’t provide 100 percent protection from pregnancy. In other words, there’s always a slight chance of pregnancy, no matter how careful you are.
Despite your birth control preferences, consider taking a test if you experience any of the signs we’ve listed.
Human error or defects can also result in unplanned pregnancy. Birth control pills can be difficult to remember to take each day. According to Planned Parenthood, 9 out of every 100 women on the pill will get pregnant if they don’t take it as directed.
Condoms can break and tear or otherwise be used incorrectly. According to Planned Parenthood, nearly 18 in every 100 women relying on condoms for contraception get pregnant each year.
If you’re worried about contraceptive failure, ask your doctor about alternative contraceptive methods, such as an intrauterine device (IUD). According to Planned Parenthood, less than one out of every 100 women using an IUD gets pregnant each year.
Sexually active women in their reproductive years have a chance of pregnancy every month, even when using protection. There are certain signals your body might send that should prompt you to take a pregnancy test.
For the best results, take the test after you think you’ve missed your period. Test during your first morning bathroom visit, or hold it for several hours to increase the concentration of the HCG hormone that the test measures.
Testing early helps to ensure that you get proper care for yourself and, if applicable, prenatal care for your baby. In the event of a positive result, contact your doctor as soon as possible to discuss your options and potential next steps.