What is the principle of the test for determining pregnancy?
Regardless of the type of test (test strip, tablet, electronic), the principle of its action is based on determining the level of human chorionic hormone, the concentration of which begins to increase dramatically in the body almost immediately after conception. Normally, in a non-pregnant woman, its urine level should not exceed 0-5 mU / ml. The increase in concentration is observed about 7 days after the onset of pregnancy.
What types of pregnancy testing tests exist and how do they work?
To begin with, let's say that what a pregnancy test looks like first of all depends on its type.
The most common and affordable of all are test strips. In appearance it is a usual paper strip on which there is a white and colored end with arrows, which indicates which side of the strip should be lowered into the container with urine.
In the pregnancy test tablet, the test strip is located inside the plastic case, in which there are 2 windows: the first - for carrying the test drop of urine, and the second shows the result.
If we talk about how the electronic pregnancy test works , then the principle of its operation does not differ from a simple test strip. Such devices have a special sampler, which can optionally be lowered into a receptacle with urine or placed under a jet. The result is read out after 3 minutes. If the test shows "+" or the word "pregnant" - you are pregnant, if "-" or "not pregnant" means no.
It must be said that of all the above, the most accurate and sensitive is the electronic test, with which you can determine the fact of pregnancy almost from the first day of the delay and even up to it.
How often are pregnancy tests wrong?
Whichever type of test for determining pregnancy a girl does not use, the probability of obtaining a false result is still present.
This fact is explained by the possibility of presence in the body of violations (ectopic pregnancy). In addition, a false result may be a consequence of past abortions, miscarriages.
Also, quite often the wrong result can be if the instructions for using the pregnancy test are not followed.
Thus, in order to obtain a reliable result in the pregnancy test, it is necessary to take into account the above facts, and if there are doubts, to conduct the test anew, but not earlier than 3 days later.