In the ovulation period of intercourse, 5 days after intercourse in the clinical detection of pregnancy chances are very very low, sperm and egg combination in the fallopian tube and then into the uterine cavity in the bed, at least 9 days to enter the uterine cavity in the bed. It takes at least 9 days for the trophoblast cells to reach the uterine cavity. It is only after this that the trophoblast cells start to secrete blood HCG and the result (+) can be detected through laboratory tests. It is recommended that it is best to test for pregnancy through blood HCG at around 17 days after coitus; and it is recommended that it is best to test for pregnancy through urine HCG at around 35 days after the menopause and morning urine can be utilized to do the test for early detection of early pregnancy. The presence of two red lines indicates pregnancy, it is recommended not to drink too much water 2 hours before leaving the urine, so as not to cause dilution of urine false (-) results.