Commonly used pregnancy test stick has 2 lines, C area and T area, C area is the quality control line, T area is the detection line, if the pregnancy test stick has abc3 lines, b, c line is the quality control line, a line is the detection line, when the a line does not show suggests no pregnancy, when the abc line shows suggests pregnancy. If the pregnancy test stick has abc3 lines, the a line is the main reference for determining whether you are pregnant or not, i.e. the detection line, the b line and the c line are the quality control line. If you are not pregnant, line a does not show up, line b and line c can show one of them or both lines show up. If you are pregnant, the a line, b line and c line will all show up, and the depth of the a line also indicates the length of the pregnancy. If the a line is lighter in color, it means a weak positive, which means an early pregnancy, and if the a line is especially obvious, it means a strong positive, which means a long pregnancy. If you find out that you are pregnant, you need to go to the hospital and have your blood tested for HCG to confirm your pregnancy.