A light color on the seventh day of blastocyst transfer is usually normal, and this result does not yet indicate a successful transfer. A light color on day 7 of blastocyst transfer may be due to the HCG (human chorionic gonadotropin) injection after the blastocyst transfer affecting the results, and the medication can cause a weak positive result on the pregnancy test. The seventh day of blastocyst implantation is a relatively early time to go for pregnancy test, at this time the trophoblast cells have not yet secreted HCG, HCG can not be detected in the urine for the time being, and the test paper can not test positive, it is recommended to wait for fourteen days after blastocyst implantation to take the morning urine and then go for test. It is normal to detect light color on the seventh day of blastocyst transfer, this result is not able to judge whether a woman is pregnant or not, it is recommended that women observe for the time being and do not need to take pregnancy test too early, the accuracy rate is relatively low. After the blastocyst transfer, go to the hospital to test the pregnancy, the professional doctor will be more accurate.