Early pregnancy blood tests are usually able to detect pregnancy about 8-10 days after intercourse, and blood tests are usually able to detect pregnancy more than 7 days after menopause. The time of blood test to detect early pregnancy generally depends on the time of the starting point, if the time of coitus is used as the starting point, generally about 7-10 days after coitus can be detected by blood test. If the time of menopause is taken as the starting point, pregnancy can be detected by blood test if the menopause lasts for more than 7 days. The blood test for pregnancy detects human chorionic gonadotropin (HCG). If the test is done too early, there is a possibility that the pregnancy may have already been detected but the HCG level is too low, which may result in a false-negative result. Women who draw blood for early pregnancy are advised to go to a regular hospital, consult a professional doctor, and cooperate with the doctor to complete the relevant examinations to avoid blind treatment.