While it is true that a human egg is only viable for 12 to 24 hours, a woman can actually get pregnant from an act of intercourse occurring anytime from about five days prior to ovulation to even occasionally two days after, for a total of about seven days.

The reason for this is that the sperm can survive up to five days inside the woman’s reproductive tract, and a woman can release two or more eggs within a 24 hour period.. Hence, for all intents and purposes, a women can get pregnant for about one week per cycle.