What are the symptoms of pregnancy in the first three days?

The first three days of pregnancy belong to the early pregnancy period. The early pregnancy period is divided into different stages according to the pregnancy period. In each stage, pregnant women have different physiological reactions. For example, one month into pregnancy, pregnant women will feel breast pain. In the second month of pregnancy, pregnant women will experience various pregnancy reactions, such as nausea and vomiting, drowsiness, fatigue, loss of appetite, etc. Below, we will introduce the various symptoms of early pregnancy in detail!

1. The first month of pregnancy (1 to 4 weeks)

If the menstrual cycle of a pregnant woman is 28 to 30 days, the pregnancy time is calculated from the first day of the next menstruation. The second week of pregnancy is the time when the sperm and egg combine and conception occurs. After fertilization, the cells continue to divide and soon become a solid cell mass, shaped like a mulberry, which is called a mulberry embryo. Cell division occurs as the fertilized egg travels along the fallopian tube toward the uterus. About 4 days after fertilization, the fertilized egg reaches the uterus.

In the third week of pregnancy, the cell mass sheds its outer membrane in preparation for implantation. At this time, there are about 150 cells, which differentiate into two parts: the inner cell mass is the future fetus, and the outer layer of cells will form the placenta and amniotic sac in the future. The blastocyst is implanted into the spongy endometrium rich in nutrients and oxygen, completing implantation. At this time, a large amount of oxygen, protein, vitamins and various other molecules in the pregnant woman's blood pass through the thin villus wall and continuously enter the embryo's blood flow.

By the fourth week of pregnancy, the blastocyst has been firmly implanted in the human uterus, where it grows and develops into a tiny embryo. At this time, when the menstruation is about to come, the pregnant woman's initial feeling is fullness and tenderness in the breasts, and at the same time the menstruation has not come, she should consider whether she is pregnant. The 3rd to 4th week of pregnancy is called the embryonic bud stage. The embryonic bud is about 0.5 to 1 cm long and shaped like a small seahorse. This period is the growth period of important organs.

2. Second month of pregnancy (5-8 weeks)

If menstruation has not come by the fifth week and the basal body temperature is high for more than 16 days, you can go to the hospital for a urine test. If the pregnancy test is positive, it can be basically confirmed that you are pregnant. At this time, pregnant women begin to experience pregnancy reactions, such as loss of appetite, anorexia, nausea, vomiting, drowsiness, fatigue, chills and coldness, and even sentimentality and irritability. Some parts of the pregnant woman's body also begin to change: breast swelling, darkening of nipples and areolas, increased urine and vaginal discharge, etc. These are physiological phenomena and there is no need to feel anxious about them. During the second month of gestation, the embryo has a body and a "tail". The eyes can be distinguished, as well as the small ridges on the hands and feet, which will later become fingers and toes.

During the fifth week of gestation, the embryo's neural tube begins to form. These neural tubes will later develop into the brain and spine.

Around 7 weeks of pregnancy: The fetus is about 2 to 3 cm long and weighs about 4 grams. It has grown hands and feet, and the eyes, ears, and mouth can be roughly seen. The face is beginning to look like a human.

3. Third month of pregnancy (9-12 weeks)

By the ninth week of pregnancy, the embryo's face has distinct features, its body has elongated and straightened, and its tail has shortened to disappear. By the tenth week, the embryonic period ends and the fetal period begins. The fetus's anthropometric features are clearly evident, with fingers and toes already visible. The umbilical cord also gradually grows longer, and the fetus can move freely in the amniotic fluid. At this time, the fetus' heart, liver, stomach, intestines, etc. are more developed, the kidneys are also gradually developed, produce urine, and have ureters, so the fetus can excrete trace amounts.