I'm currently in RCIA (neither because I'm trying to marry a Catholic or have been brainwashed but because I actually want to believe it or not) and I'm pretty sure up until I started I didn't know that "Virgin Birth" was a thing, I had always through that Mary's (alleged, if Christianity isn't your thing) conceiving of Jesus was referred to as the Immaculate Conception. As far as I know it seems this is a pretty common misconception (no pun intended) and I'm just wondering when it started/where it came from. Considering the church/Christians consider the Immaculate Conception to be the conception of Mary and the Virgin Birth to be the conception/birth of Jesus--both of which are super important cornerstones of the formation/foundation of the Christian faith--how did "Immaculate Conception" basically come to replace "Virgin Birth?"

I hope this is the right sub (since r/ChristianHistory is pretty dead) as although it's a question about a religious principle I'm wondering at what point in history did this terminology change happen among common people.

EDIT: I'm realizing in my title "Virgin Birth" probably shouldn't have quotes around it, my b