The egg is within 2mm in size and is the largest cell in the body, colorless and translucent. Eggs within 2mm in diameter are produced by the ovaries and are the reproductive cells of the female. The eggs are expelled by the follicles, which can be monitored by ultrasound on the 10th day of menstruation to observe the development of the follicles. When the dominant follicle grows to 18-25mm, it will expel the egg within 10 hours and the egg has a survival time of two days. In a normal woman, only one mature egg is expelled each month. The eggs may be discharged from both ovaries in turn, or continuously from one side. If ultrasound monitoring reveals that the follicle is unable to expel an egg, you can take medication to regulate it under the guidance of your doctor. In normal life, pay more attention to rest and exercise more. Not having intercourse during menstruation and not being exposed to toxic and harmful environment can improve the quality of eggs.