If I recall my kids catechism, the “Immaculate Conception” was the conception of Mary—not Jesus. The thought being that she was without sin, and was created without sin.
Not saying I buy any of it...(I am not Catholic) just trying to be precise in the language.
That is what I said that the RCs think—conceptio. Of Mary in her mother’s womb, which if so(a d it is ‘t so) that would have made Mary “sinless” at birth, hence able to haveJesus made from her flesh. All very unscientific, in onsistent with gentic biology. Where would Jesus have gotten the Y chromosome? From her? She did not have any.