Different theologies about the Immaculate Conception

I am currently having a discussion with a Protestant on the terms "Immaculate Conception" and Virgin Birth.

I have been reading the debate on Helium.com on the queston: "Was Jesus mother Mary human or divine?" Amazng how many said she was "divine."

As I was reading the "Human" side of the debate, I noted a lot of authors referred to the "Immaculate Conception" as meaning "having no sex" and applying to Jesus conception. There also seemed to be some confusion about the Virgin Birth.

When I queried Helium about this, I was told that this is a Protestant teaching.

If I could ask Scott Hahn, or someone like him, who knows, intimately, both the Catholic and Protesant theological writers, on this issue, I would like t know who the prominent Protestant theologicans are and what they say about this issue. Did they really attribute the Immaculate
Conception to Jesus, meaning he was conceived without sex?

I would appreciate having .org or .edu references from established theologians (both Protestant and Catholic) on this issue.

(My understanding of the Catholic position was that Duns Scotus debated Thomas Aquinas on this issue and established that Mary was conceived without sin (The Immaculate Conception) and that later a Pope promulgated the Immaculate Conception as dogma. A few years after that Bernadette at Lourdes said her "beautiful lady" identified herself as "I am the Immaculate Conception.") I have no references for this either.

Can you help? Thank you.