Pregnancy can be detected by blood human chorionic gonadotropin HCG in the first 10 days of pregnancy, but it cannot be detected by early pregnancy test paper or pregnancy test stick, which is mainly related to the testing method.
After intercourse during ovulation, the sperm and egg combine to form a fertilized egg, and it will implant, and HCG in the blood and urine will rise, so you can determine whether you are pregnant by drawing blood or testing urine.
Generally the trophoblast cells in the body will continue to secrete HCG after the fertilized egg has been laid for about 7 days, and the HCG in the body will rise significantly, and pregnancy can be detected by drawing blood and checking the blood HCG, which is more accurate.
If the use of early pregnancy test paper or pregnancy stick test may not be detected, because the HCG content in the urine is low, generally in about 2 weeks after intercourse will be significantly higher, you can use the test paper to detect pregnancy, or wait until the menstrual period is postponed for 3 to 7 days to detect pregnancy.
If you suspect pregnancy after intercourse, it is recommended that you take a blood test for HCG one week after intercourse, which is an earlier and more accurate way to check for pregnancy.