9 months before Jesus was born. If he had had an earthly father by natural means, Jesus would not have been the Perfect Sacrifice... After Adam, all mankind are born into a fallen world... not fit for the Kingdom... Jesus made the way for us.. and Jesus had to be the Perfect Sacrifice.. and He was.
Did not Jesus have an earthly mother? Most protestants on this forum claim she was not a virgin and was a sinner, both in original sin and subsequent sins.
If Mary, the Blessed Mother, was such a sinner, how could Jesus Christ been the "Perfect Sacrifice"? Maybe some of your protestant buddies will try to rescue you, but it will be to no avail. She is blessed among women and so is the fruit of Her womb.