A healthy couple, one without fertility problems, has about a 20 to 25% chance of conceiving during every cycle, even if they have intercourse daily. There are many reasons for this, including the fact that despite ovulation, some egg cells are incapable of being fertilized, or some of the fertilized cells are unable to implant or develop further. During the first year of trying, however, between 80 and 90% of couples manage to conceive.