not.
It is true that the Church teaches that Mary was "ever virgin".
Of course, this is nothing new. There are a lot of writings from the Fathers of the Church that defend her perpetual virginity:
http://www.cin.org/users/jgallegos/virgin.htm
Mary was the spouse of the Holy Spirit & St. Joseph never would have had conjugal relations with her as that would have greatly defiled her under Jewish Law.
http://www.cin.org/users/james/files/talmud.htm
It also fits with the biblical passages where the angel tells Mary that she will bear a child and Mary is baffled, "How can this be"? She was already betrothed to St. Joseph, under normal circumstances she would have known exactly how she was going to bear a child, but the tradition has been that she had taken a perpetual vow of celibacy to God, which was unusual, but not unheard of at the time. Writings at the time suggest that St. Joseph may have been advanced in age and already had children and agreed to marry her despite her vow of celibacy.
If interested, you can watch/hear Trent Horn explain the doctrine of the Perpetual Virginity of Mary:
http://www.catholic.com/video/the-perpetual-virginity-of-mary
or Tim Staple's explanation:
http://www.catholic.com/video/a-defense-of-marys-perpetual-virginity
How We Know Mary Was a Perpetual Virgin
Tim Staples
http://www.catholic.com/blog/tim-staples/how-we-know-mary-was-a-perpetual-virgin-0
Some other more in depth writings of the early Christians:
The Protoevangelium of James
http://www.newadvent.org/fathers/0847.htm
The Perpetual Virginity of Blessed Mary
St. Jerome
Against Helvidius
http://www.clerus.org/clerus/dati/2001-02/17-999999/virginity.html
The Perpetual Virginity of Mary
http://www.catholic.com/topic/the-perpetual-virginity-of-mary
More Reasons for Mary's Perpetual Virginity
http://www.catholic.com/blog/tim-staples/more-reasons-for-marys-perpetual-virginity