Pregnancy Test Q&As
Few women may receive a false positive result due to: chemical pregnancy, miscarriage, blood or protein in the urine, certain health conditions, or taking certain medicines that could elevate hCG levels. Although very rare, some women may receive a false negative result if their HCG Levels are not high enough yet to reach the tests cut off level. When taking the pregnancy test before your next expected period and find a very faint Test line, please test again after 2~3 days to confirm your results. If the positive Test line is getting darker and more solid, then you may be pregnant.
Tip: Do not read the results after 5 minutes to avoid inaccurate results. The T line must be a pinkish hue to be considered a true positive within 3 – 5 minutes.
A false positive is when a test result shows pregnancy, when in fact there is no pregnancy. It is usually caused by one of these reasons:
- Chemical pregnancy: Also known as early miscarriage, about 25% of all pregnancies are subject to this outcome. This usually occurs when the pregnancy is lost shortly after implantation. The pregnancy test may still show positive results for some time after a miscarriage because it takes time for HCG levels to drop again.
- Missed reaction time: It is imperative to follow the instructions included with the pregnancy test carefully. The manufacturer provides a time frame for processing test results and reading the results before or after the recommended time could cause the test results to be inaccurate. Ghost lines have been known to appear before or after the allotted processing time. Any results interpreted after 5 minutes must be considered invalid as it could be a false positive result.
- Chemical interference : If you are undergoing fertility treatments and have recently received a HCG shot, the hormone from the shot must be cleared from your system before the test can give reliable results. Doctors recommend waiting 14 days before testing as a general rule to clear the body of excess HCG. Testing before that time may trigger a false positive result. Other factors that could interfere with HCG levels in the body include age, certain hormonal medications, and health conditions. Another common chemical interference is when the sample used to take the test has been contaminated. This can happen due to the presence of soap or dish detergent residue and lead to a false positive. It is important to be sure that when taking the test, you use a fresh plastic cup or just take a test that allows you to urinate directly on the stick.
- Evaporation line: This goes back to the ghost line mentioned under “Missed Reaction Time”. Any line that is horizontal and/or presents in a different color other than the specified testing color can be misinterpreted as a positive result. Our line should show up as a rosy pink color. If the test shows a grayish line, the results should be interpreted as a false positive and a re-test should be performed. You can also contact your doctor for a follow-up blood test if you are experiencing early pregnancy symptoms.
A false negative is when the pregnancy test tests negative for pregnancy, when the woman is in fact pregnant. This does not occur often with our pregnancy tests, but here are some reasons this could occur:
- Testing too early: Detecting pregnancy through urine testing comes later than detecting through a blood, even though the HCG levels do increase rapidly in the first few days (they will double every 48-72 hours). If you take a pregnancy test at day 6 or 7 after ovulation, it is highly possible that even if you have conceived, you will not have enough HCG present in your urine to trigger a positive result. A negative result in those early days would be a false negative.
- Test sensitivity: There are a few pregnancy test brands offering cut off levels of 20 mlU/ml or lower, which does allow for earlier detection but also has a higher possibility of false positives. Our pregnancy tests however, use the FDA-recommended standard of 25 mlU/ml to lower the chances of false positives.
- Hook effect: "Hook effect" can also cause false-negative results in normal pregnancies when an excess of hCG is present. HCG builds up very quickly and may reach very high level by 5 weeks of pregnancy (i.e. 3 weeks after the expected period). If you search "Hook Effect HCG" on internet, you should find a lot of resource about this common effect. Also "Hook effect " can be easily figured out by diluting urine so HCG level can be lower than "Hook effect" level and get very bold positive results.
- Urine is too dilute: Women who drink lots of liquid and/or urinate frequently may not realize that they are lowering the amount of HCG that is detectable in the urine. If you received a negative result on a pregnancy test but expect a positive result, try testing again first thing in the morning as your urine then will have the most concentrated amounts of HCG.
Fortunately it is easy to determine if you are a victim of a false negative result. Simply test again in a couple of days. For very best results, be sure to test using first morning urine and a highly sensitive early pregnancy test.
There are many reasons an invalid test result may occur. We would like to share some common, possible reasons with you.
- There was not enough of the urine sample to saturate the test strip.
- The test strip was dipped past the max line per instructions. If user urinates onto the absorbent pad, it is easy to spill over to pass the max line if the urine stream is too fast.
- Using an old or diluted urine sample. It is recommended to use a morning sample to avoid dilution.
- The test strip did not sit long enough in the sample. You should keep the tip in urine until dye rises into the results window. (Est. time: 5-10 seconds)
- In a very unlikely situation, people are using a test strip that has an expired date, has been left out for an extended period outside of the foil packet, exposed to heat or cold (store between 39-86°F) or a used test strip. All of these may cause an invalid response.
Home pregnancy tests (HPTs) are designed to detect HCG, a hormone released by the placenta right after the embryo begins implanting into the uterine lining. The hormone is released in a pregnant woman's urine.
FDA recommended cut-off level is 25 mlU/ml HCG and Easy@Home pregnancy tests comply with the same standard. The accuracy detecting HCG above cut off is over 99.8% when used properly.
Though a positive result should not change for several days, a negative result may change to a false positive within minutes after the end of the testing period, which would not be an accurate reading. It is always best to read the results within the 5 minute testing period and then discard the test to avoid confusion.
Your HCG levels may take up to 9 weeks to return to normal levels from a previous pregnancy. If you test during this time, it’s impossible to know if a “positive” result is accurate. This is because the test cannot distinguish between the HCG present from a previous pregnancy and the HCG due a current pregnancy. In addition, your menstrual cycle may be irregular. If you don’t know when your next period is due, we recommend testing 19 days from the last time you had unprotected sex or first day of your missed period. If you receive a negative result but are experiencing early pregnancy symptoms, re-test within 48 hours. Confirmation with a doctor may be needed to follow-up.
No. Each urine sample will vary in its chemical makeup, as will the humidity of the air in testing chamber (room). Such variations in physical conditions can cause the vertical streaking and/or pink-rose background color but will not affect the test results. Normally the pink-rose background should be cleared after 3 minutes. As long as the control band appears within five minutes, the test is working properly.
No, variations in color of the control band will not affect the test result. Please note however that ghost lines have been known to appear before or after the allotted processing time. Any results interpreted after 5 minutes must be considered invalid as it could be a false positive result.
We suggest that you limit your fluid intake for about two hours before you collect your urine. Heavy intake of fluids prior to testing will dilute the hormone in your urine. The best time to take the test is first thing in the morning, because that is when the urine is most concentrated.
Because birth control pills work with hormones that are present in every woman's body at all times and a pregnancy test only detects a single hormone that is specific to pregnancy, birth control pills cannot cause a false-positive pregnancy test. According to the National Institute of Health, the design and chemical specificity of a pregnancy test makes it impossible for birth control hormones to cause a false positive.
According to Planned Parenthood, birth control pills are considered 99 percent effective when they are taken correctly. So, only about one out of every one hundred women who take birth control pills will get pregnant while taking them as prescribed.
However, many women have trouble remembering to take them at the same time every day, or may take them with other medications that interfere with their effectiveness, such as antibiotics. Or, they may have other medical conditions that prevent birth control pills from limiting a woman's fertility. In these instances, pregnancy can occur.
You may take a home pregnancy test any time you suspect that you may be pregnant. However, the chances for a false negative will be reduced if you wait until the day you would normally expect your period to start. Taking the test before this day can give you a positive if indeed you are pregnant, but you may get a false negative if you have not had enough time between conception and testing for the HCG to build up to detectable levels in your blood stream.
If you are taking birth control pills, your pill pack should tell you when to expect your period. However, some birth control pills limit the number of periods that you have during a year. If you suspect that you may be pregnant while taking these types of pills, testing 12 to 14 days after you suspect conception should give you a reliable positive or negative result.
Our pregnancy test tests for the presence of human chorionic gonadotropin (HCG). The presence of HCG indicates pregnancy and will appear in urine very early in the pregnancy.
To work out when your period is expected, calculate your usual cycle length by counting the number of days from the first day of your period until the day before your next period starts. If you have irregular cycles, you should allow for your longest cycle in recent months before testing. If you have no idea when your period is expected, we recommend testing not less than 19 days after the last time you had unprotected sex.
Due to the science and chemistry behind the majority of pregnancy tests out there, extremely high levels of HCG isn't able to be detected. This is called "the hook effect". We recommend diluting your urine with water and trying again.
Early morning urine samples tend to be the best kind, especially in early detection. This is because not urinating all night will cause the HCG concentration to be greater, making it easier to detect.
Fertility medicines that contain HCG, such as Profasi, will produce a false positive the pregnancy test is used soon after taking the medication.
The pregnancy test is sensitive to the amount of HCG in the urine. If there is less, then the line will be fainter. An initial faint line that steadily gets more solid with more time and tests indicates pregnancy. (Please note that a pregnancy test result is no longer dependable if it had been sitting out for more than 5 minutes).
If the control line does not appear, we recommend doing it over with a different test strip, even if the second line does appear.
When exposed to cold temperatures and frozen, the pregnancy tests still can be used to three months or longer depending on the length of frozen time and expiry date. In the instructions we mentioned “Do not freeze." because our claimed shelf life is 2 years since the manufacturing date. If frozen, the shelf life will be sooner than the expiration date printed on the pouch. Therefore, to make sure test can be used before expiration date, manufacturer requires "Do not freeze."
It is very important before usage, please make sure the tests are back to room temperature (39.2ºF ~86 ºF) and avoid freezing the product again.