The scriptural fact that Blue Duncan mentioned was that Mary had to undergo purification "according to the Law of Moses". It does not mean the Evangelist believed she was objectively impure, as another example of following the ritual despite the absence of objective need was the baptism of Christ, as Adiareton cogently points out.
Regardless of the physiological manner of Christ's birth, the scripture is silent on the issue of Mary loing her virginity or having other children. This is one instance when adherance to the Scripture Alone superstition would do you untold good.
It is all good for you to focus on the sacrifice and resurrection of Christ, if you do not wish to also focus on the Incarnation, the other pillar of Christian faith. One way to do so is to refrain from blaspheming the Holy Mother of God and find something positive to say, in the spirit of the, hm, "holiday" season.
Yikes!