Please choose the correct ending to complete the given sentence: Health: [header] How to determine fertility [title] Understand the biology of your body. [step] Most women are only fertile for a few days out of every. [substeps] During ovulation, when the ovaries release an egg, your body has a short window during which the egg can be fertilized.

Ending1: For this period of time, you are considered fertile, and conception is possible. Sperm can survive in a woman's reproductive tract for up to five days, meaning you could potentially become pregnant from intercourse that took place prior to ovulation if the mucus conditions in your body are receptive. Ending2: This window, called the ovulatory period, occurs about 20 to 30 days prior to ovulation. The length of time to ovulate varies from woman to woman, but 4 to 6 days is always good. Ending3: Ovulation happens often during periods of high-level fertility where fertilization failure is considered safe for women. Women can even start their own ovulation cycle without having to undergo a period to become fertile at all. Ending4: The female will have one egg in the insemination chamber and one in the sperm chamber. It is not recommended that you have more than two eggs in your uterus at one time.

Answer format: ending1/ending2/ending3/ending4