Clinically, the spermatozoa will not be alone, but the fertilized egg will be implanted. After implantation of the fertilized egg, it will take about half a month before the corresponding early pregnancy reaction will gradually appear. After the fertilization, the trophoblast cells start to secrete blood HCG, and the corresponding reaction will occur when the concentration of blood HCG is relatively high. However, due to individual differences, the time of early pregnancy reaction may vary, some may be earlier and some may be later. In addition, some people may have severe reactions and may not be able to eat and need to be treated with fluids to correct electrolyte disturbances. Some people will have relatively mild reactions and will be able to pass the time of early pregnancy reaction safely with clinical adjustment of diet. Therefore, it is recommended that once early pregnancy reaction occurs, try to eat if you can, so as to reduce the occurrence of nausea and vomiting aggravated by friction of the gastric mucosa in the fasting state.