It’s NOT that hard (no pun intended) to have unprotected sex with one’s Mrs. and not have her get pregnant.
There’s not a tremendous number of days in the month when a woman has a really good chance of getting pregnant.
Unfortunately, I know too many married couples that tried hard for YEARS to have a baby, even after seeing doctors and getting help, and still not succeeding.
WIFE: Honey, just came back from the gynecologist and she says I can’t have sex for three weeks.
HUSBAND: What did the dentist say?