Are you having a difficult time getting pregnant even though you and your partner have been checked and all is well?

In my practice, I see a lot of women for fertility issues. Most of the time both husband and wife are healthy. Both of them often have been tested and the results come back normal. So how come they are not getting pregnant? I have women that get sad and cry every month when their period comes, some get depressed or angry-Why do other women get pregnant and not me?- some get insomnia from over thinking and some get so tensed up, their shoulders look like they're attached to their ears.
It is not easy having to count days, or take basal daily temperature or look at the vaginal discharge just to know if ovulation is occurring. And the stress of telling the future father that it's time to perform now! This process is supposed to be fun but end up being more stressful than a root canal. Often stress is the cause!