It is not possible to detect pregnancy on two days of intercourse. If ovulation occurs on the day of intercourse, or the day before, conception can occur during intercourse. It takes about 24 hours for the sperm and egg to form a fertilized egg, and after 24 hours, it takes about four days for the egg to be partially transported to the uterine cavity by fertilization. It takes about 1-2 days for the egg to be transported to the uterine cavity and then implanted in the uterine cavity. Therefore, it takes about one week from the time of sperm-egg union to the time of implantation of the fertilized egg. During this week, the blood chorionic gonadotropin and progesterone levels do not fluctuate, so there is no way to check for pregnancy. One week later, after the fertilized egg has implanted, the chorionic gonadotropin, progesterone and estrogen levels will rise rapidly and pregnancy can be determined by checking the levels of chorionic gonadotropin, progesterone and estrogen. A urine pregnancy test can be performed 10 days after intercourse to determine if conception has occurred. If ovulation is delayed, for example, on the third day of intercourse, or within three days, there is also a possibility of conception because sperm can survive for 72 hours, in which case the time to detect pregnancy is pushed back by 1-3 days.