Final answer:
Ovulation typically occurs around day 14 of a 28-day menstrual cycle, with the exact timing influenced by individual cycle variations and triggered by a surge in luteinizing hormone.
Step-by-step explanation:
Ovulation, which is the release of an egg from the ovary, typically occurs at the midpoint of the menstrual cycle. For a standard 28-day cycle, this would mean that ovulation happens around day 14. However, it is important to note that the length of menstrual cycles can vary significantly among individuals, from 21 to 45 days, and that ovulation can occur on different days depending on the cycle length. During ovulation, a surge in luteinizing hormone (LH) triggered by rising estrogen levels from the maturing follicle prompts the release of the egg. Once released, the egg enters the fallopian tube where it may meet sperm and become fertilized.