At the choice of the buyer, pharmacy chains present a lot of different diagnostic devices for early detection of pregnancy. The so-called strip strips are very popular. They are easy to use and reasonably priced.
Inkjet, tablet tests are more expensive, but they are considered more reliable. Be that as it may, the test shows pregnancy only at a certain concentration of human chorionic gonadotropin (a specific hormone) in the urine. It occurs immediately after the implantation (introduction) of the embryo into the endometrium (inner layer of the uterus). Initially, it rises in the blood and only after a few days is found in the urine. You can reliably find out about the conception that has taken place before the delay only by a blood test for hCG.
If you take a pregnancy test (before or after the delay, it doesn’t matter), then the reagent on the device will start looking for hCG. When a hormone is detected, the device will show its effect. In most tests, this is expressed as a second strip. The first band that appears indicates the correctness of the testing, it is a control one.
Equally important is the sensitivity of the device. Most tests have a range of 20-25 mIU. That is, they will determine pregnancy when there is such a level of hCG in the urine and not before. Tests with a sensitivity of 10 mIU are positioned more accurately.
However, they have a large error and can often give a false positive result. Electronic devices, according to manufacturers, are able to show an accurate result as early as 10 days after ovulation. However, some of them determine the period with an accuracy of up to a week.
The principle is to determine not only the presence, but also the level of hCG, because the longer the period, the more of that hormone in the blood and urine.