When you are following the course of pregnancy, physicians will usually determine the dates of "sacred" to have sex. These dates are in your fertile period. You only have six most fertile days in a month to do the insemination. At the time ovulation occurs, ie when the mature egg cell that has been released from the uterus, into the fallopian tubes for fertilization. At this stage, the sperm (which can last more than 100 hours) must be at the top of the fallopian tube or oviduct when the egg is released from the ovary.

The problem is sometimes difficult to know exactly when you ovulate. Women generally have 26-32 day menstrual cycle. If your menstrual cycle 28 days, you'll usually ovulate on day 14. However, if your menstrual cycle exactly 28 days every month too, ovulation does not necessarily occur at the same time every cycle.

"It would help if you notice symptoms of ovulation, some of which are marked by changes in cervical mucus that is more transparent," said Paula Hillard, MD, associate professor of obstetrics and gynecology at Stanford University School of Medicine in Palo Alto, California. Another sign of ovulation is pain on one side and this is when you have to focus sex.

Conception more likely to occur when intercourse before ovulation rather than afterwards. The best strategy to allow the occurrence of conception is to have sex at least once every two days during the fertile period. Usually you will be asked to relate once every two days, from day-to-8 (after the first menses day) until day 19 of your cycle.