Basically, pregnancy cannot be detected 10 days after intercourse, because most women will not have a fertilized egg until 15 days after intercourse, and only after the egg has been laid will the trophoblast cells start to secrete blood HCG, which can only be detected clinically through a blood test, so pregnancy cannot be detected 10 days after intercourse. It is recommended that if the test is done by blood HCG, it can be done 16 days after intercourse. If you want to use urine to check HCG, it is recommended that it is best to use morning urine for early pregnancy testing 20 days after intercourse, as the clinical chance of a positive result is relatively high if you are pregnant, and it is also recommended that when using morning urine for testing, you should not drink too much water two hours in advance to avoid dilution of urine, which may lead to false negative results.