Three days of pregnancy is usually no reaction, almost around 6 weeks of pregnancy may appear early pregnancy reaction; however, there are a small number of people, the entire pregnancy without early pregnancy reaction. When you are newly pregnant, the hormone levels in your body have not changed much yet, so the possibility of having an early pregnancy reaction is also relatively small, and you usually do not have any obvious reaction. If it is around 7-10 days after conception, there may be reactions during the period of implantation, such as mild abdominal pain and bleeding. As the fertilized egg completes its implantation, it may also be accompanied by nausea, vomiting, dizziness, and fatigue. If you want to test for pregnancy, you can seek medical attention about 10 days after intercourse for a blood test to determine if you are pregnant. If there is any abnormality, it is recommended to consult a doctor in time.