Early pregnancy test strips can be detected as early as 10 days after intercourse, but at this time one strip is very dark and the other bar is very light. To be accurate, it is best to check half a month after intercourse, because the chorionic gonadotropin level in the urine is higher at this time, and you can clearly see that the two bars are red, which can confirm early pregnancy. As the fetus increases in size, the level of hormones secreted by the fetus will also increase. If you want the early pregnancy test to be accurate, you can use the girl’s first urine in the morning, because the first urine is more concentrated and the hormone content inside is higher, so the false-positive or false-negative rate of the test is lower.