Ten days after intercourse, a line is detected, this result is negative, but it does not necessarily mean that you are not pregnant. This is because the fertilized egg will not be laid until about a week after intercourse, and then human chorionic gonadotropin (HCG) will be produced. A blood test for human chorionic gonadotropin can be done about 10 days after intercourse to find out if you are pregnant. It is still a little early to test with a pregnancy test, which should be taken two weeks after intercourse to basically find out if you are pregnant. To be on the safe side, you can wait until your period is delayed, usually more than 7 days after your period is delayed, and use the early pregnancy test paper to test more accurately. So 10 days after intercourse, a line is measured, not necessarily not pregnant.