The 13-day intercourse blood HCG test, if it is pregnant, it usually has a value of around 100-200 IU/L in international standard units. If it is less than 100IU/L, it is possible that it is a biochemical pregnancy. If it is more than 100-200 IU/L, it is basically normal. Whether it is normal or not also depends on the doubling of HCG on the next day. The HCG increase on the next day should be more than 1.7-2.0 times to be normal. Generally, there is no clinical rule on what value of HCG is normal, but only a general range. The HCG growth can indirectly reflect the quality of the embryo and its development. You can check the progesterone, as long as the progesterone is not too low above 20nmol/L, you can basically maintain the pregnancy, the main thing is to monitor the HCG index.