The first thing many women do after missing a period is purchase a home pregnancy test. Available without a prescription, home pregnancy tests can be purchased at most drugstores, supermarkets and grocery stores. These tests allow women to test for pregnancy as soon as they begin to notice pregnancy symptoms rather than wait for a doctor’s appointment. Early pregnancy detection gives women the opportunity to begin prenatal care as early as possible. A home pregnancy test is not a foolproof method of detecting a pregnancy because to is susceptible to errors due to user error. Knowing what is involved with home pregnancy testing prior to taking the test can help ensure that the test is performed properly, significantly increasing the odds of an accurate result.
Knowing when to take a home pregnancy test all depends on the test manufacturer. While just about all home pregnancy tests will detect a pregnancy shortly after a missed period, there are some manufacturers who have developed tests that can confirm a pregnancy as early as 7 days prior to a missed period. These early detection tests, however, have a higher incidence of false negatives. This is because some pregnant women will not have enough pregnancy hormones circulating in their blood this early. For this reason, it is best to take a pregnancy test at least one week after a missed period. Women who take a test earlier than that and get a negative result should retest a few days later if their period does not begin.
There are several options for home pregnancy tests. The majority of home pregnancy tests require the woman to insert the tip of a dipstick into their urine, midstream.
There are a few different ways to reveal the test result. This varies among manufacturers. Some brands offer multiple testing kits, each with a different method of reading results.
If the line is present in the control window, the test has worked. The second window is the test window.
Home pregnancy tests contain sensitive antibodies that detect tiny amounts of the pregnancy hormone HCG in urine. After the egg is fertilized it will implant into the uterus. The fertilized egg, or embryo, will then begin to release HCG into the body. HCG is needed for the pregnancy to grow and thrive. This hormone is secreted approximately one week before a missed period. The amount of HCG present in early pregnancy varies among women. While some women will have enough HCG to detect a pregnancy prior to a missed period, others will not have enough until two weeks later.
All pregnancy tests are regulated by the Food and Drug Administration (FDA), which means that all pregnancy test manufacturers have to live up to the same standards. For this reason, all brands are relatively equal in accurately detecting pregnancy. Most tests have an accuracy rate of 99 percent in detecting pregnancy when used at least one day after a missed period. Home pregnancy tests administered after a missed period are usually very reliable as long as testing is done correctly and according to instructions.
False positives are relatively rare, but can sometimes occur. Women who are taking fertility medications that contain HCG can have a false positive result. False positives can also occur in women who have recently been pregnant, women who have ovarian cysts and women going through menopause.Still relatively uncommon, false negatives occur much more often than false positives.
The main reason for a false negative is testing too early. The development of tests that claim to detect HCG up to a week before a missed period lead many women to test earlier. Although some women will have a positive test at this early stage, many will not, even if they are in fact pregnant. Testing a few days after a missed period decreases the chance of a false positive by up to 70 percent.
Another factor in false negatives is improper timing. If the test is checked for a result before the urine has had a chance to interact with the HCG-detecting antibodies in the test, the symbol that identifies pregnancy may not have time to show up. Always follow the package instructions and wait the designated amount of time before reading results. All test results should be considered invalid after one hour.
First morning urine is recommended when testing for pregnancy. This is because the urine is more concentrated and has not been diluted from drinking liquids. Testing midday or in the evening can lead to a false negative is the urine is not concentrated enough.