After the first trimester, the estrogen in the body increases thousands of times, and the clinical manifestations differ from one pregnant woman to another. Most of them have clinical symptoms such as nausea, vomiting, anorexia, and local changes in the breasts, such as enlargement of the breasts and coloring of the nipples and areolas. There is also a feeling of sleepiness and fatigue caused by the increase in estrogen. It is recommended that during the first trimester of pregnancy, in addition to dietary adjustments, you should also take proper rest and avoid sexual intercourse during the first three months of pregnancy, because the embryo is still unstable at this time and if you have sex, it may cause a miscarriage. It is normal to feel sleepy and tired in the early stages of pregnancy.