The T zone is the detection zone, which is the part that indicates whether you are pregnant or not, if the detection zone appears red, you can be sure that you are pregnant, if it appears colorless, which means no color, you are not pregnant, It can be compared to the color of the test area to determine whether it is positive, weakly positive or negative. The principle of pregnancy test is that after pregnancy, the embryo will secrete a large amount of human chorionic gonadotropin and release it into the blood, and the urine is the filtrate of the blood, and there will be a certain amount of human chorionic gonadotropin in the urine, so it is possible to determine whether you are pregnant by testing the urine.