What happens to the egg follicle in the ovary as FSH rises during days 1-12?

As follicle-stimulating hormone (FSH) levels rise during days 1-12 of the menstrual cycle, several ovarian follicles begin to mature. FSH stimulates the growth and development of these follicles, leading to an increase in estrogen production from the growing follicles. Typically, one dominant follicle emerges while the others undergo atresia, preparing for ovulation. This process is crucial for the regulation of the menstrual cycle and preparation for a potential pregnancy.