Pregnancy can be detected with 3 days to menstruation, but it can only be determined by a blood test. If a fertilized egg is laid after intercourse, the hormone level in the body will change and the human chorionic gonadotropin in the body will slowly increase over time, and at first it will increase exponentially, so the HCG test can determine if you are pregnant. If you want to test with a pregnancy test, you need to wait for about 7-10 days after your period before you can take the test, and you cannot check before your period. Therefore, women should pay attention to their physical symptoms, and if they want to know quickly whether they are pregnant or not, they can take a blood test. It is important to keep an empty stomach before the blood test to be able to determine whether you are pregnant or not.