Why is that when you take a HPT and it comes up negative there's still a slight chance that you may be pregnant. However, if it comes up positive it's just positive and you are pregnant? I'm pretty sure how the test works and about the HCG(?) in the urine being at different levels than your blood. I just want to know why the test would give such shaky results.
2006-10-18 03:11:10 · 11 answers · asked by hey_girl21 1 in Pregnancy & Parenting ➔ Pregnancy
Hormone levels are different at different times of the day, different dates through the pregnancy etc. If the test does not detect enough of the hormone it will give you a negative result, HOWEVER, that doesn't mean you're not pregnant all the time, just that the hormone level was not high enough to be detected. 3 days later, the hormone levels are almost double and if you are pregnant they will show up.
A false positive is rare because other than certain medications and a recent miscarriage your body will not contain the HGC hormone in levels that are detected by the test.
HGC is produced when the egg is fertilized and begins to implant into the uterine wall. After 3 months a pregnancy test will come back negative because the hormone is no longer released.
2006-10-18 03:50:14 · answer #1 · answered by Anonymous · 0⤊ 2⤋
The human growth hormone is first released by the body into the blood, so the highest concentrations of the hormone from the on set of pregnancy are in the blood.
Like all things, what is in the blood is eventually expelled through fecal matter and urine as the body recycles and makes more hormones.
There is a peak in the HGC hormone at what would be the onset of your period, this extremely high level of the HGC hormone is what causes your body to switch from mestration mode to pregnancy mode. It takes more hormones to be detected on a urine test (ppm) than a doctors blood test.
Some women's body produce a lower peak that others, which is enough to comense pregnancy, but still not high enough in the urine to produce a positive result on the urine test.
All that said, If you test too early, miscalculate your LMP, or ovulated later than expected, or just dont produce enough hormones you can get a false negative on the home pregnancy test.
The test is 99.7% effective at detecting such hormone, but in a few rare cases the test is faulty and you get two lines, or a positive by mistake. Or in some rare cases you can be one certain medications (usually theyre for fertility and you're doctor warns you of false positives on home pregnancy tests) that cause a positive result. Lastly, you can have a chemical pregnancy, which simply means that you were pregnant, produced the hormone, miscarried without realizing, and the hormones havent returned to normal. These cases are all so very very rare that its simpler to say that you cannot get a fase positive.
:)
2006-10-18 03:23:59 · answer #2 · answered by amosunknown 7 · 0⤊ 0⤋
The test detects a certan level of HCG. You could be pregnant and get a false negative because the HCG level is still too low for the test to detect. Once the test detects it then it's picking up the HCG in your urine. Blood test are more sensitive and can pick up the low HCG levels sooner then a urine test.
2006-10-18 03:19:50 · answer #3 · answered by ktpb 4 · 0⤊ 0⤋
Like you said it measures the hcg levels. Every woman has hcg in their body whether they are pregnant or not. But the test has to measure over a certain amount of hcg to determine pregnancy. So if it has rose above that amount then you are pregnant because your hcg has increased. If it shows negative then it is possible that the levels just havent risen enough.
2006-10-18 03:15:16 · answer #4 · answered by sweetm12004 5 · 0⤊ 0⤋
Different tests are designed to detect different amounts of the hCG hormone. If your levels aren't high enough to activate the strip then you will get a negative result, even though you may have a baby! Positive results are positive because the tests are designed to ONLY react if the levels of hCG are adequate to activate them. Blood tests are so accrurate because they detect even the smallest change in your hormone levels, it doesn't require any kind of certain level to indicate pregnancy, just one higher than the norm.
2006-10-18 03:15:00 · answer #5 · answered by justwondering 5 · 3⤊ 0⤋
To get a false negative, the hgc in the urine would be too dilute to detect in a hpt. As far as false positives go, there aren't any chemicals I can think of that would trigger a positive result.
2006-10-18 03:39:11 · answer #6 · answered by dr_imzadi 4 · 0⤊ 0⤋
If it's negative you may be pregnant but there is not enough hormone detected to show a poitive reading.
If it says positive then it has picked up enough hormone and this is accurate, as you wouldn't have that level of hormone if your weren't pregnant.
Hope that helped x
2006-10-18 03:15:11 · answer #7 · answered by vanessa s 4 · 2⤊ 0⤋
he only way you can get a false pos is if your on fertility drugs that contain hcg, some will say that a chemical pregnancy causes it too but since a chemical pregnancy is just a very early miscarriage and techniquely you were preggo to start with then i dont consider that false
2006-10-18 03:22:46 · answer #8 · answered by Anonymous · 0⤊ 0⤋
Charity sounds like she knows what's she talking about. I wouldn't have come up with that.
2006-10-18 03:19:18 · answer #9 · answered by Anonymous · 0⤊ 0⤋
it would come up negative only if you are not pregnant and that is 100 per cent because there no hormone present.
2006-10-18 03:15:52 · answer #10 · answered by twinsters 4 · 0⤊ 2⤋