The monthly cycle and becoming pregnant
However, by understanding exactly how conception works and its relation to the menstrual cycle, it can be possible for prospective parents to increase their chances of having a child - and there are also numerous treatments available for the same purpose.
By timing their attempts to get pregnant in line with the point of their cycle that they're at, women can increase the likelihood of their egg being fertilised during sexual intercourse.
At the time of the month that a woman's ovary releases an egg, the womb lining thickens to prepare for the potential that it will be needed to harbour a fertilised egg.
If that doesn't occur then this is when a woman will have her period, as the lining of the womb breaks down if no egg attempts to implant itself.
By having sex at the point of the cycle where a woman is most fertile it is possible for couples to increase their chance of having a child, so those who are trying for children are often advised to closely monitor the female's menstrual cycle.
If this is successful and an egg is fertilised, it will then implant itself on the womb and is known as a zygote. After eight weeks the zygote is then called am embryo before later developing into a foetus.
In the majority of cases a missed period is the first sign that a woman is pregnant, and this can be confirmed by a urine test a few days after she would have expected her period to start.
For those who are experiencing genuine fertility problems, there are treatments available to help both men and women tackle the issue.