During which phase of the menstrual cycle do Days 1-14 occur?

Days 1-14 of the menstrual cycle occur during the follicular phase. This phase begins on the first day of menstruation and lasts until ovulation. During the follicular phase, the primary focus is on the maturation of ovarian follicles, stimulated by the increase in follicle-stimulating hormone (FSH). As the follicles mature, they produce estrogen, which helps to regenerate the endometrial lining of the uterus in preparation for a potential pregnancy.

This phase also includes the ovulatory phase, which occurs at the end of the follicular phase just before ovulation; however, the entire span of Days 1-14 is primarily categorized as the follicular phase. Thus, the correct answer highlights the overall process of follicular development and hormonal changes leading up to ovulation, marking it as a significant part of the menstrual cycle.