I wiil delve here into the realm of blasphemy to see what the consensus is.
Mat 1:18 Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child of the Holy Ghost.
Mat 1:19 Then Joseph her husband, being a just [man], and not willing to make her a publick example, was minded to put her away privily.
Mat 1:20 But while he thought on these things, behold, the angel of the Lord appeared unto him in a dream, saying, Joseph, thou son of David, fear not to take unto thee Mary thy wife: for that which is conceived in her is of the Holy Ghost.
This really strikes me as the words describing Mary as being pregnant by another man before her and Joseph consumated their relationship.In order to avoid disgrace they agree to use the notion of divine pregnancy (you would think Holy Ghost would know how to use a condom.)and in this way gain a respect of sorts that would serve them since I am sure the consequences would otherwise be extreme.
One last thought (for now) what exactly happened to all the descedants of Mary and Joseph? You would think that they would keep a running record at least even if they had to be secretive to avoid prosecution.After all it would be highly prestigious to be in direct line to the mother of Jesus right?