Early pregnancy test paper dry with a light mark, is the phenomenon caused by crystallization of urine after drying, test paper dry regardless of whether there is no clear meaning of the mark. Because the specific gravity of urine is different for each person, the crystalline components in urine are also different, and not everyone will have crystalline components after testing. Early pregnancy test is checked with the first urine of the morning urine, and the results need to be seen within 3-5 minutes after the test is accurate. There are 2 test lines on the early pregnancy test paper, one is the contrast line, as long as there is urine contrast line will appear red, the other line appears red only to suggest the possibility of pregnancy. If the number of days of pregnancy is small, the other line may appear red and not obvious, that is, weakly positive, and the color will gradually deepen when tested again after an interval of 2 days, or the blood HCG test can be performed, and the result will be more accurate.