Hi Lampo,
It is not church teaching that Mary felt no pain.
What may have you confused is the common belief that Mary did not feel the pains of childbirth. The Church teaches that Mary was ever a virgin : before, during and after the birth of Jesus. This means that she maintained her physical integrity during childbirth.It is reasonable then to believe that Mary did not feel the pains of childbirth. John Paul II said that Mary’s pain was felt on Calvary when she brought us forth as her spiritual children, offering her Divine Son to the Father as a participant in our redemption.
Verbum