The Greek word that's eventually translated to English "virgin" means unwed. (I have no source at hand to support that.)
Let's employ Occam's razor.
Mary (lit. Beloved) is just some dirt poor farmers daughter who got knocked up and ran away to the next village with her boy friend. Gave birth in a barn.
Then 25 years later this dude shows up again, a carpenter by trade, and is a total hippie.
Then all his mates write down his adventures in letters to each other.
Mary wasn't the virgin, her mother was. She had to be pure that way to carry jebus. It's so nonsensical even the followers of the religion get their own shit wrong.
I thought immaculate conception was the idea that Christians had about heritable sin from Adam and Eve, and that when Mary was conceived the sin associated with humanity in general skipped her somehow. Virgin birth, something separate, was Mary making Jesus via parthogenesis and Bible magic. Someone correct me if I'm wrong I grew up in a cult so I got half of this off the internet.