Even the earliest pregnancy test works the same way as all the others. It tests for the hormone hCG in the urine. This is considered to be a pregnancy hormone. It is a hormone that is released by the placenta soon after the egg gets fertilized and gets implanted into the lining of the uterus.
Measuring units of the pregnancy test that is the earliest
The sensitivity of the pregnancy tests is measured in mIU. A test having the sensitivity of 20 mIU is more sensitive than one of 50 mIU. The more sensitive a test is, the earlier it can detect a pregnancy and the lower the number is, the more sensitive the test gets.
The pregnancy test that gives the earliest result has a sensitivity of about 20 mIU, and this means that the test is able to detect a pregnancy about 8 days after the egg has been implanted.
How soon can you use a pregnancy test?
In case you would like to use the earliest pregnancy test then you should know that at about 10 days after ovulation should be of 25 mIU, and of 50 mIU after 12 days. In two weeks this level rises to 100 mIU. In case of blood tests, a test can be done at about 5 days, when the level is of only 5 mIU .
Nonetheless even in case of the pregnancy test that is the earliest there is the risk of a false negative. This is caused by the fact that there could be some levels of hCG in the system of women even without the presence of a pregnancy.
The earliest pregnancy test that you will find in the drugstores has a sensitivity of 50 mIU or 100 mIU. Nonetheless you can also find on the internet some tests with the sensitivity of 20 mIU. In case you would like to know which test to choose, you should take a look at the tables presenting their sensitivity.
How to use the pregnancy test that is the earliest?
In case to find out about your pregnancy as soon as possible, you should make sure to use your morning urine. This is because in the morning the hCG levels are the highest. In case you cannot use the morning urine, you should wait for several hours before taking the test.
Even if you are using the earliest pregnancy test, in case you urinate frequently or you have diluted urine, the test could detect low levels of hCG.
Still it is possible that you are pregnant, but the test cannot pick up the real hCG levels.
It is possible that you are using the pregnancy test that is the earliest and you still get a faint line. Even if you get such a result it means that you are pregnant if you read it in the indicated time frame of 5-10 minutes. If you use the earliest pregnancy test correctly the faint line is a positive result.