Ovulation lasts for 12 to 48 hours, but you are potentially fertile for up to seven days, and maybe up to 10 days, according to the most optimistic studies. This is because sperm can survive up to five days in the female reproductive tract.
Ovulation is when an egg is released from an ovary. That egg survives for up to 48 hours before it can no longer be fertilized by sperm. This short time may be considered the ovulation period. However, your total fertile period is how long the egg is fertile and how long sperm can wait for the egg combined. This is known as your Fertile Window.
While you are possibly fertile for seven days out of your cycle, the odds of conceiving at the far ends of that time period are small.
If you want to get pregnant, you should have sex two to three days before you ovulate, of-course, with correct sperm taken.