The fastest swimmers may find the egg in as little as 45 minutes. It can take the slowest up to 12 hours. If the sperm don't find an egg in the fallopian tubes at the time of intercourse, they can survive inside you for up to seven days . This means that if you ovulate within this time window you could still conceive.
Five days before ovulation: 0.4 percent to 7 percent chance you'll conceive
Four days before ovulation: 8 percent to 17 percent
Three days before ovulation: 8 percent to 23 percent
Two days before ovulation: 13 percent to 29
One day before ovulation: 21 percent to 34 percent [/s[/
Ovulation day: 8 percent to 33 percent
One day past ovulation: 0.8 percent to 11 percent
Two days past: 3 percent to 9 percent