Ideally, sexual intercourse should takes place as close to ovulation as possible (time of release of the oocyte from the ovary). The spermatozoa can survive 2-3 days, but the oocyte is only there for 12-24 hours. To increase your chances of conception it would be ideal for you to have sexual intercourse 1 to 2 days prior to ovulation. Hence a large number of spermatozoa will be present in the fallopian tube awaiting ovulation. Of course it is not always possible to predict exactly when a woman ovulates. This depends on the length of the menstrual cycle, even though recent studies have shown that he window of ovulation may vary more than previously believed, even when the menstrual cycle is normal. At this point it must be noted that it is wrong for a couple only to focus their sexual intercourse during the potential ovulation period. This leads to increased stress levels, especially when there is a negative pregnancy test and also minimizes the pleasure of sexual intercourse, without significantly increasing the percentage of a positive outcome. At least 2- 3 times a week are enough to achieve a pregnancy in most couples. Increased number of sexual intercourse does not cause a problem.