Heres a new interesting discovery. They say there is a flash of light at the moment of conception.
Mary was not an unmarried woman or "unwed mother". She was betrothed to Joseph, which in the custom of the time was the first stage of marriage. After betrothal, when the husband had built or obtained a home for them, the couple would then come together. In Matthew 1:18-19 we hear:
Now the birth of Jesus Christ took place in this way. When his mother Mary had been betrothed to Joseph, before they came together she was found to be with child of the Holy Spirit; and her husband Joseph, being a just man and unwilling to put her to shame, resolved to send her away quietly.