You're more likely to become pregnant in any particular month if you have intercourse during your most fertile period - the days just before and after you ovulate. Ovulation usually occurs about 14 days before the start of your next menstrual period. If you would like to figure out when you're likely to ovulate next, you'll need to know the approximate length of your menstrual cycle. Fertilization occurs when a sperm penetrates the egg - and this typically takes place in one of the fallopian tubes. The fertilized egg then travels to uterus and implants in the uterine lining.
Dr Naveen Kumar M, The Apollo clinic, J.P.Nagar,B'lore