Test strips usually refer to early pregnancy test strips, which measure hCG in urine. it is generally recommended to test through morning urine 10 days after intercourse or after menstruation has been delayed for accurate results. Early pregnancy test strips are used to determine if you are pregnant by measuring the level of hCG in your urine, which can only be secreted after the fertilized egg has implanted in the womb. hCG can generally be detected as elevated in the urine about 10 days after ovulation. It is recommended to use morning urine because the concentration of hCG in urine at this time is relatively high and less affected by diet and other factors, making it easier to detect and the results are relatively accurate. If the test result shows two red bars, it is certain that you are pregnant; if the monitoring result shows one red bar, it is recommended to retest again after an interval of 3 days, and if it is still negative, pregnancy can be ruled out. When the results of early pregnancy test paper are not convincing enough, the most accurate way is to collect venous blood from the hospital after 10 days of pregnancy and test the level of human chorionic gonadotropin to determine whether you are pregnant or not.