Usually, you can use an early pregnancy test 10-14 days after the last intercourse to find out if you are pregnant. If you are in a hurry, you can actually come to the hospital for a blood test for HCG more than 10 days after intercourse to rule out the possibility of pregnancy. Because the fertilized egg starts to secrete HCG on the sixth day, it can be detected after 11 days. In early pregnancy, HCG secretion increases very quickly, usually doubling in 2 days, therefore, after having intercourse during ovulation, a blood test for HCG can be done around 9-11 days to confirm whether you are pregnant or not. The test paper is relatively inaccurate compared to the blood draw, but the blood test for HCG is the gold standard.