On the sixth day of blastocyst transfer, a pregnancy test with one deep and one light is normal, you may be pregnant, you should go to the examination immediately to determine whether you are pregnant. After blastocyst transplantation, generally on the fifth day, it starts to implant in the uterine lining, after the implantation of blastocyst, the trophoblast cells will secrete human chorionic gonadotropin and progesterone, and human chorionic gonadotropin will be dispersed to all parts of the body through the bloodstream, and also can be discharged in the urine, but due to the secretion of human chorionic gonadotropin at this time is small, which may lead to the appearance of the phenomenon of the pregnancy stick having one dark and one light. On the sixth day of blastocyst implantation, when the pregnancy test stick shows the phenomenon of one shade of dark and one shade of light, women can go to the hospital immediately to have blood drawn to test the levels of human chorionic gonadotropin and progesterone in the blood to determine whether they are pregnant or not. During pregnancy, women should pay more attention to rest, maintain a good state of mind, avoid staying up late and overworking, etc., and seek medical treatment promptly if adverse symptoms occur.