No, I would not seek to limit God whatsoever but we have the fact that an egg was fertilised in Mary's womb and then the 9 month gestation period followed where Jesus was formed and grew as all babies do.
This follows from what scripture tells us, rather than guessing what may have been.
Actually, to reach the conclusion that an egg was fertilized in Mary's womb is to guess what may have been. Here is the what scripture actually says:
"Joseph son of David, do not be afraid to take Mary home as your wife, because what is conceived in her is from the Holy Spirit." (Matthew 1:20)
""The Holy Spirit will come upon you, and the power of the Most High will overshadow you. So the holy one to be born will be called the Son of God." (Luke 1:35)
As you can see Luke doesn't come close to describing biological reproduction. And the key word on which one might suppose that in Matthew is
γεννηθεν. This word is most frequently translated "conceived" or "begotten" in the various English translations. And of course those terms in English and Greek most generally refer to biological reproduction. But, and this is key and why I say that you are guessing, THEY DON'T ALWAYS.
And all one has to do is go to scripture to see this: "Has the rain a father? Or who has begotten the drops of dew?" (Job 38:28)
Today we know that biological conception requires a human sperm and a human egg. And scripture makes it clear that no human sperm was involved. To suggest that God provided a sperm is to also suggest that God created a sperm within Mary's uterus for the conception to take place. But again, scripture does not say this, that is a guess you have made. It is just a plausible that God simply caused an embryo of his own creation to be implanted within the wall of Mary's uterus. And it is just as consistent with the Biblical text as any other guess that one might make.
Further, I want to submit that it is more consistent with the understanding of human reproduction that was held at the time of the writing of the New Testament to understand that the embryo in whole, not just the sperm, came from God. The understanding of the ancients was that the womb of the mother was merely the location of growth for the baby, that life came fully from the father. Thus inherited sin is passed down only from the father and not the mother. Motherhood consists of being an incubator and giving birth. And similarities of the child in looks or disposition to the mother is a result of having been in the womb, not genetics. Just as the same seed might grow differently in different soils. In ancient thought, Mary is the God-bearer, not the egg-provider. Given this, even to say that what was conceived in Mary was from God is to say, in the thinking of the ancients, was fully from God.
