This is how the birth of Jesus Christ came about. When his mother Mary was betrothed to Joseph, but before they lived together, she was found with child through the Holy Spirit.
Gospel's Commentary
Today we admire the greatness of St. Joseph. On the one hand, he believes that he should respect the silence of Mary, i.e., to leave her alone with the mystery of the Incarnation of the Son of God. But this is tough and, besides, how to do it?
-Joseph did not act himself; Joseph prayed and pondered. And, thus, he was enlightened by God: “do not be afraid to take Mary your wife into your home… She will bear a son and you are to name him Jesus.”