The “right time” is not only important in human life, but also in human reproduction. Each month the human egg can only be fertilized within 24 hours and in the female body sperms survive only 3 days to wait for an egg.
In any one month, it is estimated that of 100 young and healthy heterosexual couples attempting to conceive, about 25 couples will successfully do so and about 75 will fail. In the individual case other factors like age, stress, smoking and life-style can influence the result. Stress can have a negative effect on sexualtity as well as on the production of sexual hormones and ovulation. With advancing age there is a decrease in fertility (the ability to achieve a pregnancy). The decline is gradual over the reproductive life span of the woman; it is particularly noticeable over the age of 30 and accelerates between 35 and 40 so that fertility is almost zero by the age 45.
For young and healthy couples having frequent intercourse, about 70 – 80 % will be pregnant after one year of trying and about 93% will be pregnant after two years of trying to conceive.
You should visit a fertility clinic if you fail to conceive following one year of unprotected intercourse if under 35 years of age or six months if over 35.