Does it say or indicate when Mary was with child or you know when she knew she was pregnant, as in how many months she was into the pregnancy?
When Gabriel visited Mary, he said, "The Holy Spirit will come upon you, and the power of the Highest will overshadow you; therefore, also, that Holy One who is to be born will be called the Son of God. Now indeed, Elizabeth your relative has also conceived a son in her old age; and this is now the sixth month for her who was called barren. For with God nothing will be impossible" (Luke 1:35-37). Mary then accepted what God had offered her. So at this time, Mary was not yet pregnant.
Excited that her cousin was expecting, Mary rushed off to see her. "Now Mary arose in those days and went into the hill country with haste, to a city of Judah, and entered the house of Zacharias and greeted Elizabeth" (Luke 1:39-40). But Elizabeth greets her praise that she is the mother of the Lord (Luke 1:42-45). Thus she had conceived by this time and Mary acknowledged that she was given a great gift (Luke 1:48).
Mary then stayed with Elizabeth for three months, which would take her to just after the birth of John. When she returned home, she was far enough to show (Matthew 1:18), though we don't know how long it was before Joseph realized that Mary was pregnant.