If a woman with regular menstrual cycle has intercourse during ovulation, she should be able to detect pregnancy on the morning of the fifth day of delayed menstruation by taking a urine HCG test. If you want to be more accurate, you can go to the hospital and take a blood test for human chorionic gonadotropin, which is a very sensitive hormone and can detect changes in HCG in the body after the fertilized egg has been laid. If your period is delayed for five days, or if you have stopped menstruating for 35 days or so, the fertilized egg will have already been deposited, and a blood test to check for HCG will be able to detect the pregnancy. In general, doctors recommend that patients prefer the blood test method, because it is more accurate, and you can monitor the changes in blood HCG to understand the development of the embryo.