High levels of HCG in early pregnancy prevent antibodies from binding to the hormone, so when a test pack is checked, the results are negative. This condition is known as the prozone effect. So, getting pregnant with twins and having a negative test pack is possible.
Lastly: sometimes twin or higher order multiple pregnancies, in which levels of hCG are very high, can cause a false negative pregnancy test. This is called the high-dose hook effect. 4 It's unusual, but possible. if you miss a period and have pregnancy symptoms, see your doctor.
Even if you are pregnant with twins, there's no guarantee you will produce hCG any sooner than if you were pregnant with one baby. But because your levels may be higher, it is possible to detect a pregnancy slightly earlier due to higher levels of hCG.
If you feel as though you're pregnant but got a negative home pregnancy test result, your symptoms could be down to premenstrual syndrome (PMS) or you may have taken the test too early.
That said, hCG levels vary from person to person and pregnancy to pregnancy, so hCG levels are not definitive to determine a twin pregnancy. Some people have high hCG levels and only give birth to one baby; others have exceptionally low hCG levels and give birth to multiples.
Specifically, twin and multiple pregnancies can have 30% to 50% higher hCG levels than singleton pregnancies at the same point in early pregnancy.
Trusted SourceNational Institutes of HealthPregnancy TestSee All Sources It takes a few days for the hCG production of twins to outpace the hCG production of one baby. In fact, on the first day of your first missed period, there might be no difference at all.
Is it possible to have a negative pregnancy test but still be pregnant? Yes, it's possible to be pregnant and have a negative pregnancy test result. In fact, some researchers estimate this happens with up to 5 percent of home pregnancy tests. It's called a "false negative" pregnancy test result.
It appears shortly after the embryo attaches to the wall of the uterus. If you are pregnant, this hormone increases very rapidly. If you have a 28 day menstrual cycle, you can detect hCG in your urine 12-15 days after ovulation.
In which week of pregnancy will an ultrasound show twins? Your healthcare provider will be able to determine if you're having twins at your first ultrasound, which often takes place at about 12 weeks.
In cases of multiple gestations and gestational trophoblastic disease, the etiology of false-negative UPTs is suspected to be due to very high urine hCG concentrations, resulting in the hook effect or prozone phenomenon [6].
You cannot conclusively distinguish a single pregnancy from twins on a urine pregnancy test. That said, you may have a very early positive pregnancy test if you are carrying twins.
A normal pregnancy may have low hCG levels and result in a perfectly healthy baby. The results from an ultrasound after 5 -6 weeks gestation are much more accurate than using hCG numbers.
Can Too Much Pee on a Pregnancy Test Make It Negative? Urinating too much on a urine pregnancy test should not cause a false negative result. But diluted urine, or urine with a higher water content, can impact a pregnancy test by skewing results.
Urine pregnancy tests rely on hCG in your urine. Test too early and the amount of hCG in your urine isn't detectable. As many as 9 out of 15 women will get a false negative until seven or eight weeks of pregnancy.
False Negative Results
A false negative means the test is negative, indicating you are not pregnant, but you actually are pregnant. This result can occur if the blood pregnancy test was performed too early, when there is not enough hCG in the blood to detect a pregnancy.
could i still be pregnant? If you take a pregnancy test after your period is late and get a negative result, you're unlikely to be pregnant. Home pregnancy tests are very accurate — about 99 percent — but a false negative is still possible. Try taking another pregnancy test in a day or two to double check.
To get a positive pregnancy test, most women will have to wait 5-10 days after their period was due. Some may detect pregnancy earlier becuase hCG accumulates at different rates for different women.
Range of hCG levels and what they can mean
The range for singletons is 5 – 397 and for twins it is 48 – 683. As you can see, there is a big overlap between the first hCG level in singleton and twins. What this means is that even if you have a first hCG level of 397, it could be a singleton pregnancy.
An immediate dark positive result could mean that there's a high concentration of hCG in your urine, and the test is showing an immediate dark result due to the hormone level. One thing to note is that all home pregnancy tests are different and may detect hCG at different levels.