I am acting like the Bible is sufficient for our faith without jumping up and down and getting hot and bothered about extra-Biblical details like whether or not Mary had pain when giving birth.
Depicting Theotokos as giving a "natural" Birth, is a specualtion and very much extra-Biblical, because the Bible says nothing about it.
The Church has reason to believe what we believe about BEV Mary. We do not claim it as dogma. We only claim that she is the Mother of God, our Lord Jesus Christ, her Motherhood not being a "natural" one, from the Incarnation through the His Birth.
We Orthodox and Catholics do not believe that she suffered in her Virginal Birth any pains because the Birth, like the Incarnation itself, was a supernatural act of Divine intervention and not of carnal relationship subject to physiological consequences and corruption.
Just as the incarnation itself was nothing "natural" it is only consistent to consider the Virginal Birth as nothing "natural."