Ovulation is a crucial phase in a woman’s menstrual cycle when a mature egg (ovum) is released from one of the ovaries. This typically occurs around the middle of the menstrual cycle, which is roughly 14 days before the next expected period in women with a regular 28-day cycle. However, it’s important to note that cycle lengths can vary significantly, and ovulation can happen anywhere between days 10 and 20.

Here’s a simplified breakdown of the process:

1. Follicle development: During the first half of the cycle, a follicle, a small sac within the ovary, matures and contains a developing egg.
2. Hormonal surge: As the follicle matures, it produces increasing amounts of estrogen, which stimulates the lining of the uterus (endometrium) to thicken in preparation for a potential pregnancy.
3. LH surge: A mid-cycle surge in luteinizing hormone (LH) triggers ovulation. This surge typically lasts for 24-48 hours and is the most fertile time of the cycle.
4. Egg release: The LH surge causes the follicle to rupture, releasing the mature egg from the ovary.
5. Egg transport: The egg is swept into the fallopian tube by finger-like projections called fimbriae.
6. Fertilization window: The egg remains viable for about 24 hours after ovulation, waiting for potential fertilization by sperm. If fertilization doesn’t occur, the egg and thickened uterine lining are shed during menstruation.

Knowing the days you are most likely to be fertile can increase your chance of getting pregnant. The typical menstrual cycle is 28 days long, but each woman is different. There are about 6 days during each menstrual cycle when you can get pregnant. This is called your fertile window. Use the calculator to see which days you are most likely to be fertile.