Most manufacturers of tests for definition of pregnancy is recommended only suppress the delay of the next menstruation. In the instructions you can see the recommendation that you need to collect urine in the morning, not afternoon or evening.
As you know, pregnancy can occur if the unprotected intercourse was on the day of ovulation or the day before. Then the fertilized egg moves through the fallopian tube within 5-10 days, after which there is implantation - the attachment of the ovum to the uterine wall. After implantation in the blood appears the pregnancy hormone HCG, while its number of daily doubles.
A pregnancy test determines the content of HCG in the urine of women, hormone levels are somewhat lower than in the blood. This should be taken into account to choose the best time to conduct the test. The results of testing conducted in the morning immediately after waking up, will be more accurate than the indicators in the urine collected in the afternoon or evening, as the concentration of HCG morning urine is higher.
To know when to do pregnancy test, it is possible to carry out approximate calculations of growth hormone levels of pregnancy.
If you take the test strip, the user can see its sensitivity. The ordinary test, it is 25 mUI. If the level of HCG exceeded this boundary, the analysis result is positive.
For our calculations we will use the pregnancy test with a sensitivity of 25 mUI. The test reacts to the presence of the pregnancy hormone HCG in a woman's blood. With a sensitivity of 25 mUI test can show a positive result if the woman's urine a hormone HCG exceeded this level
If we take as a starting point the date of unprotected intercourse, coinciding with the day of ovulation, and take to calculate the average number of days before implantation, it can be assumed that on the seventh day the contents of HCG in the blood increased to 2 mUI. Then on the eleventh day after ovulation, its quantity increases to 36 mUI and only this day, the test can show the presence of pregnancy.
Most likely, the second stick will be weak, as in the urine is emitted less of the pregnancy hormone, and the calculated figure will barely hold on to the bar the sensitivity of the test.
For the average woman, ovulation occurs 14 days before the next menstruation. Thus, a pregnancy test may be positive even for 3 days to delay.
But if implantation was late, and the fertilized egg is implanted only on the tenth day, the test will be positive only after a delay period.
Currently selling to get a more sensitive test strips. Therefore, answering the question, when is the best time to do such a test for pregnancy, it can be noted that to determine the presence of a baby in the tummy of the girl is possible before the delay.