Once an egg is released, it has 24 hours to get fertilized before it dissolves. However, sperm can live for up to 5 days inside a woman. From 5 days before ovulation through the day of ovulation is the Fertile Window.
According to Dr. Wilcox, the likely hood of conceiving is distributed for a total of 6 days including the ovulation day. You can increase your chances of getting pregnant if you have more than one relationship during this six-day period.
SmileReader tells you two or three days with the most likely to be pregnant with a smiling baby. If you are planning on getting pregnant, do not miss the day when you see and heard the smiley baby!
Source: Wilcox, AJ, et al., 1995, "Timing of sexual intercourse in relation to ovulation-effects on the probability of conception, survival of the pregnancy, and sex of the baby, "NEJM, 333 (23)