8 Things You Didn't Know About Your Period

Ovulation, which lasts one to two days, refers to the phase in your menstrual cycle when your ovary releases an egg for fertilization. According to Dr. Wider, subtle changes that may happen before and during ovulation are breast tenderness, a rise in basal body temperature and an increase in cervical mucus—which are all biology's way of prepping for fertilization. While some may not notice any specific changes, others feel ovulation more pointedly. "Some women experience mittelschmerz, which is lower abdominal pain that occurs with ovulation," she explains. Just before ovulation, with the help of estrogen, a follicle develops within the tissue of the ovary. When the egg is released, the follicle ruptures, causing fluid to be released into the abdominal cavity, which can be irritating for some women. "Some even feel it on one side of their abdomen one month and on the other the next month, since our ovaries take turns releasing eggs."