Phantom hCG

his is known as a false-negative — and it's much more likely to occur than is afalse-positive. You might get a false-negative if you: Take the test too early. The earlier after a missed period that you take a home pregnancy test, the harder it is for the test to detect HCG.Home pregnancy tests work by detecting the presence of the hormone called “human chorionic gonadotropin” (hCG) in urine. HCG is a hormone secreted by the embryo once it has implanted into the wall of the uterus, which typically occurs 6-8 days after conception (or 7-10 days post ovulation).Mar 20, 201How do you do this test? For most home pregnancy tests, you either hold a test strip in your urine stream or you collect your urine in a cup and dip your test strip into the cup. If you are pregnant, most test strips produce a colored line, but this will depend on the brand you purchased. Read the instructions for the test you bought and follow them carefully. Make sure you know how to get good results. The test usually takes only about 5 minutes.

The different tests for sale vary in their abilities to detect low levels of hCG. For the most reliable results, test 1-2 weeks after you miss your period. There are some tests for sale that are sensitive enough to show you are pregnant before you miss your period.

You can improve your chances for an accurate result by using your first morning urine for the test. If you are pregnant, it will have more hCG in it than later urines. If you think you are pregnant, but your first test was negative, you can take the test again after several days. Since the amount of hCG increases rapidly when you are pregnant, you may get a positive test on later days. Some test kits come with more than one test in them to allow you to repeat the test.

O negative test results mean that you are not pregnant? No, there are several reasons why you could receive false negative test results. If you tested too early in your cycle, your placenta may not have had time to produce enough hCG for the test to detect. Or, you may not have waited long enough before you took this test. 

If you have a negative result, you would be wise to consider this a tentative finding. You should not use medications and should consider avoiding potentially harmful behaviors, such as smoking or drinking alcohol, until you have greater certainty that you are not pregnant.

You will probably recognize incorrect results with the passage of time. You may detect false negatives by the unexpected onset of menses (regular vaginal bleeding associated with “periods”.) Repeat testing and/or other investigations such as ultrasound may provide corrected results.

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