Symptoms after egg and sperm fusion

Everyone knows that when the sperm and egg combine effectively, the gestation of life begins, but we cannot see when the sperm and egg combine with our naked eyes. For many couples who are preparing for pregnancy, they are very concerned about whether they can successfully conceive. In fact, after the sperm and egg combine, some changes will occur in the female body, such as a drop in body temperature, slight pain in the lower abdomen, and symptoms similar to a cold.

Question 1

When the sperm and egg combine successfully and implant, your basal body temperature will drop first, and some people will also experience bleeding. People with sensitive senses may experience soreness or pain, while others may experience cold-like symptoms. To sum up, there are four points:

1. Decreased basal body temperature

2. Dull pain in the abdomen

3. I feel like I have a cold

4. Breast pain and nipple tenderness

Question 2

Sperm and egg combine

Sperm can survive in the female fallopian tube for 1-3 days, and the egg can survive for about 1 day. If sexual intercourse occurs within a few days before or after a woman's ovulation, the sperm and egg may meet in the ampulla of the fallopian tube. At this time, a group of sperm surround the egg. The capacitated sperm secrete acrosome enzymes from their heads to dissolve the corona radiata and zona pellucida around the egg, opening a path for the sperm to enter the egg. In the end, only one sperm enters the egg. After the sperm completely enters the egg, through nuclear fusion, the 23 chromosomes from the father and the mother are combined into 46 (23 pairs) chromosomes, and then a new cell is formed. This cell is called a fertilized egg or pregnant egg. This process is called fertilization. This is the beginning of a new life.

The fertilized egg undergoes cell division 24 hours after fertilization. The fertilized egg absorbs nutrients and oxygen from the fluid secreted by the fallopian tube and continues to undergo cell division. At the same time, through the peristalsis of the fallopian tube, the fertilized egg gradually moves towards the uterine cavity and reaches the uterine cavity after 3-4 days.

Question 3

After the blastocyst implants, its cells continue to differentiate to form three germ layers: ectoderm, mesoderm and endoderm, and accordingly develop into various tissues and organs of the fetus at different gestational weeks. The ectoderm is mainly differentiated into the nervous system, skin epidermis and hair; the mesoderm is mainly differentiated into muscles, bones, blood system, circulatory system and most of the urogenital system; the endoderm is mainly differentiated into epithelial tissue of the digestive system, respiratory system and related glands. 5-8 weeks after menstruation, the fertilized egg develops into an embryo, and then develops into a fetus after 9 weeks. Fetal appendages such as the placenta are formed partly from the differentiation of blastocyst cells and partly from the differentiation of maternal cells.