Ten days after unprotected sex, a blood test for pedestrian chorionic gonadotropin (HCG) can be a relatively accurate determination of pregnancy. HCG is a glycoprotein hormone produced by the placenta after conception in women. It is an important indicator for diagnosing early pregnancy, monitoring early pregnancy reactions, and trophoblastic tumors. Normal women’s blood tests for HCG are negative or the concentration is small, and the indicator rises during the first week of pregnancy. Therefore, it is more accurate to perform a blood human chorionic gonadotropin HCG test to diagnose pregnancy ten days after sexual intercourse. However, it should be noted that in the event of pregnancy, it is recommended to carry out a systematic examination to exclude ectopic pregnancy and other conditions.