I think is not so much of a myth, but a misunderstanding. I am repeatedly amazed by the number of patients, who during an initial consultation, have revealed their lack of understanding in regards to the ideal timing of intercourse. This surprisingly can even still be the case after previous medical consultation. Surely the timing of sex should be first point to be clarified.
To make it clear, it is not best to have sex at the time of ovulation. Instead, it is best to have sex before-hand. Given the right conditions, it is possible for sperm to survive for up to five days inside a woman. On average, with the right conditions of cervical mucus, the sperm is expected to last for three days. In contrast, the egg will only last somewhere between 12 to 24 hours once it is released. Ideally, it is best to have sex before ovulation and have the sperm in place waiting for the arrival of the egg.
The trick then becomes to figure out in advance when ovulation will occur. The most common way to do this is to use an ovulation predictor kit (OPK). These measure the Luteinising Hormone surge which occurs in the process of ovulation. They offer a 24-36-hour warning before the egg is released. OPKs can however be unreliable. You may need to try a couple of brands before you find which is best for you. OPKs are either saliva or urine tests and they can be purchased from pharmacies.
*This is the fourth of a list of 13 myths concerning conception which was compiled by Dr Minna Geisler from The Waterstone Clinic in Ireland.