The blastocyst transfer test paper may show a gray mark for 7-8 days, but this has no diagnostic significance, and a positive test paper result has to be monitored to show that the blastocyst transfer is likely to be successful. Wait for 14 days after the blastocyst transfer and then use the test paper to take a pregnancy test, the test paper may show two positive bars, accompanied by a delay in menstruation, basically indicating that the woman is pregnant. Blastocyst transfer test paper may show gray marks in 7~8 days, but the gray marks have no diagnostic significance and cannot indicate that the blastocyst has been successful, blastocyst transfer test paper should not be used too early to detect pregnancy, the accuracy of the test is not high. After 14 days of blastocyst transfer, you can use the test paper to test pregnancy, at first, try to choose morning urine to test, the concentration of human chorionic gonadotropin in the morning urine is higher, and the result of the test is also more accurate, and you should master the correct method, in order to improve the accuracy of the test paper. You can also go to the hospital for a blood test after blastocyst transfer to improve the accuracy.