Pregnancy can be detected the day after a normal implantation bleed due to the fact that after the sperm and egg combine to form a fertilized egg, it takes about six days for it to begin to implant. At this time, the trophoblast cells of the fertilized egg begin to produce HCG, which can be detected in the woman’s blood about a day later. If you want to know if you are pregnant sooner, you need to go to the hospital for a blood test. If you don’t have such conditions, you can also use urine test at home, which is later than blood test. It takes about 10 days after intercourse to be able to detect it, and the first urine in the morning will be more accurate due to its higher concentration.