If the second line of the early pregnancy test is lighter, it is common for the following reasons: the first reason is that the pregnancy is relatively short and the concentration of HCG in the urine has not yet reached the level of a strong positive result on the test paper, in which case the two lines are basically the same when the test is done again 5 days later using the morning urine. The second reason is due to ectopic pregnancy. In the early stage of ectopic pregnancy, the urine HCG may be weakly positive, which means that the second line is shallow, and in this case, if the test is repeated 5 days later, the two red lines are still dark and light. In this case, the urine may have been diluted due to drinking too much water before the urine specimen was taken, which may have caused the weak positive result.