Pregnancy: 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.
How accurate are pregnancy tests?
Pregnancy tests are super accurate when you use them correctly. The pregnancy tests you get at the drugstore work 99 out of 100 times. They’re just as accurate as a urine pregnancy test that you’d get at a doctor’s office.
Pregnancy tests work by checking your urine (pee) for a hormone called human chorionic gonadotropin (HCG). Your body only makes this hormone if you’re pregnant. HCG is released when a fertilized egg attaches to the lining of your uterus — when pregnancy begins. If your pregnancy test results are positive, it means you’re pregnant. If they’re negative, it means you’re not pregnant.
Pregnancy tests are most accurate when you take them after you’ve already missed your period.
A pregnancy test will be less accurate if it’s expired or if you don’t use it the right way. So always check the expiration date on the package, and carefully read the directions that come with your pregnancy test.
How soon can I take a pregnancy test?
You can take a pregnancy test anytime after your period is late — that’s when they work the best. It’s a good idea to take a pregnancy test as soon as possible if you miss your period or think you might be pregnant.
The earlier you know you’re pregnant, the sooner you can start thinking about your options and get whatever care you need to stay healthy.
Many pregnancy tests say they work a few days before a missed period, but the results are usually less accurate then. Read the label on your pregnancy test to find out when to take a pregnancy test and how accurate it’ll be.
Sometimes a pregnancy test is able to find pregnancy hormones in your urine as early as 10 days after unprotected sex. But these results aren’t super reliable, and you may get a false positive or false negative test result.
If your periods are very irregular, or you don’t get periods at all for one reason or another, your best bet for accurate results is to take a pregnancy test 3 weeks after sex.
Where can I get a pregnancy test?
You can buy a pregnancy test at your local pharmacy, drugstore, grocery store, and some convenience or dollar stores. Pregnancy tests are usually inexpensive — they can cost as little as a dollar. Sometimes you can get a free pregnancy test at certain health centers.
You can also get a pregnancy test from your nurse or doctor, community clinic. Most health centers use the same urine pregnancy tests that you can buy in stores. Sometimes they use a blood test to test for pregnancy, but that’s usually only under special circumstances.
The normal events of pregnancy
Initiation of pregnancy
A new individual is created when the elements of a potent sperm merge with those of a fertile ovum, or egg. Before this union both the spermatozoon (sperm) and the ovum have migrated for considerable distances in order to achieve their union. A number of actively motile spermatozoa are deposited in the vagina, pass through the uterus, and invade the uterine (fallopian) tube, where they surround the ovum. The ovum has arrived there after extrusion from its follicle, or capsule, in the ovary. After it enters the tube, the ovum loses its outer layer of cells as a result of action by substances in the spermatozoa and from the lining of the tubal wall. Loss of the outer layer of the ovum allows a number of spermatozoa to penetrate the egg’s surface. Only one spermatozoon, however, normally becomes the fertilizing organism. Once it has entered the substance of the ovum, the nuclear head of this spermatozoon separates from its tail. The tail gradually disappears, but the head with its nucleus survives. As it travels toward the nucleus of the ovum (at this stage called the female pronucleus), the head enlarges and becomes the male pronucleus. The two pronuclei meet in the center of the ovum, where their threadlike chromatin material organizes into chromosomes.
Why do I need a pregnancy test?
You may need this test if you think you are pregnant. Symptoms of pregnancy vary from woman to woman, but the most common sign of early pregnancy is a missed period. Other common signs of pregnancy include:
- Swollen, tender breasts
- Frequent urination
- Nausea and vomiting (also called morning sickness)
- Bloated feeling in the abdomen
What happens during a pregnancy test?
You can get a home pregnancy test kit at the drug store without a prescription. Most are inexpensive and easy to use.
Many home pregnancy tests include a device called a dipstick. Some also include a collection cup. Your home test may include the following steps or similar steps:
- Do the test on your first urination of the morning. The test may be more accurate at this time, because morning urine usually has more HCG.
- Hold the dipstick in your urine stream for 5 to 10 seconds. For kits that include a collection cup, urinate into the cup, and insert the dipstick into the cup for 5 to 10 seconds.
- After a few minutes, the dipstick will show your results. The time to results and the way the results are shown will vary between test kit brands.
- Your dipstick may have a window or other area that shows a plus or minus sign, a single or double line, or the words “pregnant” or “not pregnant.” Your pregnancy test kit will include instructions on how to read your results.
If the results show you are not pregnant, you may want to try again in a few days, as you may have done the test too early. HCG gradually increases during pregnancy.
If your results show you are pregnant, you should make an appointment with your health care provider. Your provider may confirm your results with a physical exam and/or a blood test.
During a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This process usually takes less than five minutes.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for a pregnancy test in urine or blood.
Are there any risks to the test?
There is no known risk to having a urine test.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
What do the results means?
Your results will show whether you are pregnant. If you are pregnant, it’s important to see your health care provider as soon as possible. You may be referred to or may already be receiving care from an obstetrician/gynecologist (OB/GYN) or a midwife. These are providers who specialize in women’s health, prenatal care, and pregnancy. Regular health care visits during pregnancy can help ensure you and your baby stay healthy.
Is there anything else I need to know about a pregnancy test?
A urine pregnancy test shows whether HCG is present. HCG indicates pregnancy. A pregnancy blood test also shows the amount of HCG. If your blood tests show a very low amount of HCG, it could mean you have an ectopic pregnancy, a pregnancy that grows outside the uterus. A developing baby can’t survive an ectopic pregnancy. Without treatment, the condition can be life-threatening for a woman.