How does the pregnancy test work and after how many days of delay do you have to do it to avoid false positives and negatives?
Do you need to know more about the pregnancy test? This is the first test to determine if you are pregnant or not and for this reason it is important to know how it works and when to do it. In what situations is the pregnancy test reliable? How long does it take to take the pregnancy test? And above all, how to avoid the results that often – unfortunately – accompany pregnancy tests: false positive and false negative?
Pregnancy test: when to do it – How to find out if you are pregnant?
The pregnancy test is done in case of delayed menstruation, the first indicator of a possible conception. It is good to clarify that the do-it-yourself pregnancy test, of which there are different types on the market, measures the beta hormone HCG, namely human chorionic gonadotropin, which the cells of the forming placenta secrete as soon as the embryo is installed.
Inside the uterus. As it takes 8 days for the conceived embryo to implant, you can rely on the date of the suspected intercourse to carry out the test (for example, you can also perform the pregnancy test a week before your period ) or simply wait until 10 days have passed. Compared to the normal onset of menstruation. How do you know if you are pregnant? If there are traces of this hormone, it is extremely likely that you are. But not always.
Pregnancy test, how it works
The most used home pregnancy test is the urinary one, which detects the concentration of the beta HCG hormone in the pee . Cost ? Very low: it ranges from 4-5 euros for the more traditional models to 15-20 for the more sophisticated ones. You can buy it at the pharmacy without the need for a referral, or – for greater confidentiality – buy the pregnancy test online.
The various models can also differ significantly from each other – lately the digital pregnancy test is going strong- but the operating mechanism is common to all and is extremely simple: all you have to do is urinate in the stick, or in the glass provided, and wait a few minutes at the most.
Many women wonder: better to make the test of pregnancy in the evening or in the morning? Doctors generally recommend doing this with the first urine of the day.
The positive pregnancy test is one in which two dashes or a positive sign appear, but in electronic models the wording “pregnant” may also appear. The negative pregnancy test is one in which only one dash appears. For this type of pregnancy test, the reliability is very high, close to 100%. But be careful, because the pregnancy test is false positiveit is a rare eventuality, but still possible.
When can this occur? In the case of taking some drugs, neuroleptics, or in the presence of blood in the urine, or in the case of a technical defect or biochemical pregnancy, which occurs when the fertilised egg fails to implant itself in the uterus.
These are all quite rare eventualities. Higher, but always in proportion, is the possibility of a false negative pregnancy test, which occurs most of the time when the test is performed too early or when too much water has been drunk before the test.
Test to be done a second time
The best way to dispel doubts if you are not 100% convinced of the test result is to do it again after a few days. The verification can confirm the same results, validating them, or disavow them.
The best pregnancy test
100% safe and in the first instance it is the result of another type of test, performed by taking blood from the arm, as in common analyses: in this case the positivity leaves no room for doubt. Other types of tests are the salivary type, still semi-unknown in Italy and which have a 98% reliability, and the Canadian one-step pregnancy tests.