The virgin birth theory was added later. Its a common belief among Pagan religions. Jesus never made any such claim. The Nazareth family that Jesus came out of had been an ordinary family apart from Marrys encounter with Gabriel and Josephs dream. Joseph and Mary would have been married and their first born Jesus was one of a number of children that they had.
We can see in the reaction that other members of the tiny village of Nazareth had towards Jesus when he returned during his public teaching.
The Rejection at Nazareth
(
Mark 6:1–6;
Luke 4:16–30)
53When Jesus had finished these parables, He withdrew from that place.
54Coming to His hometown, He taught the people in their synagogue, and they were astonished. “Where did this man get such wisdom and miraculous powers?” they asked.
55“Isn’t this the carpenter’s son? Isn’t His mother’s name Mary, and aren’t His brothers James, Joseph,
g Simon, and Judas?
56Aren’t all His sisters with us as well? Where then did this man get all these things?”
57And they took offense at Him.
But Jesus said to them, “Only in his hometown and in his own household is a prophet without honor.”
58And He did not do many miracles there, because of their unbelief.
The Rejection at Nazareth
(
Mark 6:1–6;
Luke 4:16–30)
There was NO indication in the community of Nazareth that Jesus was anything other than the legitimate son. However while conceived the natural way, I do fervently believe that the miracle of the Son of God becoming the person of Mary's baby
at conception is the miracle of miracles.