How many days can a blood test check out if you are pregnant?

If blood test HCG value, is in the same room after 10 days can be checked out, because fertilized egg formation, should start implantation on the 7th day, 12 days after implantation, fertilized egg implantation process, HCG value will increase, the body's estrogen and progesterone secretion will increase. On the 10th day HCG value will exceed the normal range. If you check every other day, the HCG value doubles, so that you can accurately judge pregnancy, and the gestational sac is well developed. If the 10th day blood test, HCG value is within the normal range, this situation indicates that no fertilized eggs are formed, no pregnancy, this test method is the earliest way to judge whether pregnancy