It may be normal for the test paper not to deepen from 9 to 12 days after the transfer, and it needs to be rechecked under the supervision of a doctor. Transfer refers to the in vitro fertilization-embryo transfer technique, to be operated by a professional doctor. Generally in the embryo transfer about 1 after the implantation of the bed, but some will also be implanted late, usually not more than 7 days, only after the implantation of the bed began to secrete HCG (human chorionic gonadotropin), and the urine out of the HCG time is late, so the transplantation of 9 to 12 days of the test paper does not deepen may be normal, you can observe for another 1 week or so to check again. After the embryo transfer, we should pay attention to appropriate rest, avoid strenuous exercise and exertion, prohibit coitus, eat a light diet, avoid spicy stimulation and cold food. The blood HCG test should be carried out about 2 weeks after the transfer to determine the pregnancy, and ultrasound examination should be carried out at 4-5 weeks after the transfer to determine whether it is a normal intrauterine pregnancy.