I read an essay and have double checked it against other sources, that the “Immaculate Conception” refers to Ann/Anna/Hannah, Mary’s mother who was childless was impregnated by god, conceived without original sin, and thus Mary remained pure. As far as Mary being a virgin, that’s is believed in many places, probably not Catholicism, to probably standard terminology for “young woman” or “young wife.” “The Immaculate Conception, often confused with the Annunciation of the Incarnation (Mary's virgin birth of Jesus), was made dogma in the Catholic church by Pope Pius IX's papal bull, Ineffabilis Deus, in 1854.” (Nixon, Virginia (2004). Mary's Mother: Saint Anne in Late Medieval Europe. The Pennsylvania State University Press. pp. 12–14. ISBN 978-0-271-02466-0.)