A pregnancy test gives precise indications about the presence of a specific hormone: the hormone chorionic gonadotropin (or HCG or beta-HCG). This hormone is detectable approximately eight days after fertilization. In fact, once fertilization performed and the onset of egg, it remains free and floating in the tube until it reaches the uterine cavity and bind via one of its ends. The cells of this end will begin to secrete hormones (beta-hCG) to maintain the ovarian secretions to the rules of not returning: unique condition that the egg remains attached to the uterine wall.
It is this hormone chorionic gonadotropin, not present in females not fertilized, which is detected by pregnancy test. The amount of hCG doubles every two days until about the twelfth week of pregnancy before falling, but still detectable in the blood and urine throughout the pregnancy period. There are several types of pregnancy tests:
1 - Definition urine pregnancy test
It can detect the hormone human chorionic gonadotropin in urine by the presence of antibodies that react positively or negatively by displaying a specific color.
2 - Defining pregnancy test by blood
After an appointment with your doctor, he may prescribe a blood test at a laboratory analysis.The principle is the same as for a urine test: detection of the hormone HCG.
3 - Defining pregnancy test saliva
Its main strength lies in its ease of use. Once the pregnancy test is chosen, it is necessary to know precisely its rate of reliability, to avoid any nasty surprises ...
The operating principle of pregnancy tests is simple: we verified the presence of the hormone hCG, also known as pregnancy hormone (present only in pregnant women) in the urine of women. If so (or more precisely if there are sufficient for it to be detected), this hormone reacts with specific antibodies present on the test. This shows the little blue strip in case of positive test (according to the marks, symbols differed for positive and negative, be sure to consult the instructions to properly interpret the results).
When to do the pregnancy test?
We have said, the test is reliable if it is positive, pregnant lady is, no doubt!
However, false negatives may occur if the test is done too quickly. Indeed, growth hormone must be present in sufficient quantities in the urine to be detected by the test. So do not run too fast at the pharmacy. If your sex to carry a fertilized egg, it begins a journey along 6 to 7 days through the fallopian tube before reaching the uterus. It is only then that the embryo will implant in the uterine lining (the so-called implantation), and that the pregnancy hormone HCG begins to be produced. But it will take another few days before the rate it reaches a level sufficient to be detected by pregnancy tests. Ultimately, it will have to wait ten days between the time when fertilization has taken place and the moment you can pass this test.