In the vast majority of cases, pregnancy does not occur until about 1 month after intercourse. On the day of intercourse, if the sperm and the egg have combined, it will take about half a month before it enters the uterine cavity and lays down, and then it will grow and develop, and then it will secrete blood HCG, and with the increase of the concentration of blood HCG in the body, the corresponding clinical reactions will appear, and most of them will appear after 45 days of the menopause, such as anorexia, nausea when waking up in the morning and some people will also have Vomiting. Due to individual differences, the symptoms of nausea and vomiting are not the same, some people will be more mild, no one will be more serious, and some people even need to be hospitalized to give rehydration, to correct electrolyte disorders. Clinical reactions to early pregnancy also include localized changes in the breasts, which will enlarge and soften under the effect of estrogen, and the nipples and areolas will also appear to be colored.