It helps that it had been foretold that God would send a Messiah, a Savior. More specifically, Isaiah prophesied that "The Lord himself will give you a sign: The virgin will be with child and will give birth to a son, and will call him Immanuel" (Isaiah 7:14). Did Joseph remember that prophecy? Did he ever doubt?
For reflection: When I have doubts, do I turn to God for answers and reassurance?
Let us pray. "To you, O Lord, I lift up my soul; in you I trust, O my God. . . . Show me your ways, O Lord, teach me your paths; guide me in your truth and teach me, for you are God my Savior" (Psalm 25:1-2, 4-5).