Pregnancy can be detected by a blood draw as early as about 8-10 days, but there are some individual differences that need to be analyzed on a case-by-case basis. If you have intercourse without contraception and you have intercourse during ovulation, you have a better chance of getting pregnant. After intercourse, the sperm passes through the female reproductive tract and reaches the fallopian tubes. If there is a mature egg waiting at the fallopian tube, the sperm can unite with the egg to complete fertilization. After fertilization, the fertilized egg enters the uterine cavity through the fallopian tube and begins to settle in the uterine cavity after a period of time, which usually occurs about 3-5 days after intercourse. However, it is usually not possible to detect pregnancy at this time, and a blood test for human chorionic gonadotropin, or hCG, is required about 8-10 days after intercourse to determine if pregnancy has occurred. During the preparation period, you should strengthen your diet and nutrition, it is recommended to eat more vegetables, fruits, lean meat and eggs, do not eat spicy and stimulating foods, and take reasonable vitamin supplements.