If this question is asked from several women, it is likely that each will give a different answer. The most common belief and a widely accepted answer is the woman is fertile throughout the month except for the period of seven days when she is having her menstrual periods. Still, there are some who believe the woman is fertile after seven days of finishing her periods. The fact is there is only a small window of fertility. There are a few days where the intercourse can make her pregnant. These are not more than five days in each of her monthly cycles.
Women can maintain a careful record of the start and finishing dates of her menstrual periods. It is the best way of finding out when a woman actually ovulates.
Normally the process of ovulation takes place after 10 – 14 days of the starting date of the periods. During ovulation, the body temperature also increases. Many women can rightly detect the ovulation days by thoroughly recording their body temperature. The best time to intercourse, if somebody is using this method to time her ovulation is 5 days before the temperature starts to rise. This, in turn, means that one should have the record of several months before coming on to the accurate dates of her ovulation, and knowing when is the most fertile.
As the technology is advancing there are many other methods to detect the ovulation. There is much interactive ovulation calculating equipment. To use this sort of calculators the women only need to know the date when their last menstrual periods ended. Instead of estimating the average length of the cycle they have to add their own length of the cycle and the calculator will give them exactly when she is most fertile. If somebody wants to conceive she can start having intercourse a few days before the exact date of ovulation. As the sperms can survive in the woman’s body longer than it can do in the man’s body. It is better to know about the partner's sperm count. As if the man has a low sperm count he should not intercourse three days before the exact date of ovulation. In fact he should not even ejaculate; otherwise, he would leave with no sperms when he really had to make her pregnant.
This should be kept in mind that any method used to determine the fertile period is only an estimation of the days of ovulation. There is no method yet devised that can exactly pinpoint the time and the date of the ovulation. The use of an ovulation calculator will give you an estimated date only which normally is the 15th day from the date of the start of the menstrual period for those who have an average 28 days long cycle. This may or may not be accurate for every woman. Some may conceive after one or two days they ovulate. But conceiving after this is highly unlikely.
Unlike the sperms, the egg can only survive for 12- 24 hours after their release from the ovary. These facts are the reasons for this small fertility window.