A week before menstruation, if there is unprotected sexual intercourse, it is possible to detect pregnancy by measuring the level of human chorionic gonadotropin (hCG) through a blood test. For women with regular menstrual cycles, after sexual intercourse during ovulation and successful implantation of the fertilized egg in the body, trophoblastic cells will secrete hCG. If a pregnancy test stick is used for detection, due to the early stage of pregnancy, the hCG level in urine is relatively low, and the sensitivity of the pregnancy test stick is low. With menstruation due in a week, it is usually not detectable at this time.
After the implantation of the fertilized egg, a blood test one week later can confirm whether pregnancy has occurred. A positive result indicates pregnancy, while a negative result indicates no pregnancy. Therefore, to determine whether you are pregnant a week before menstruation, you can take a blood test to measure the hCG level without the need for fasting, as blood can be drawn at any time without affecting the test results. If pregnancy is confirmed, avoid strenuous exercise, sexual intercourse, and excessive fatigue to prevent threatened abortion.
