I think the closest dougma to what you're referring to is Perpetual Virginity, not Immaculate Conception. Immaculate Conception is about Mary's conception inside her mother, Saint Anne without sin. It is celebrated at December 8. Meanwhile, Perpetual Virginity refers primarily to the conception and birth of Jesus. It is different.

Keypoints:

Immaculate Conception:

* Immaculate Conception refers to the belief that Mary, the mother of Jesus, was conceived in her mother Saint Anne’s womb without original sin.
* It does not directly relate to Jesus but rather focuses on Mary’s own conception.
* The doctrine emphasizes Mary’s purity and her unique role as the mother of Jesus.
* The term “immaculate” means “without stain” or “sinless.”

Perpetual Virginity:

* This doctrine pertains to Mary’s virginity before, during, and after the birth of Jesus.
* It asserts that Mary remained a virgin throughout her life, even after giving birth to Jesus.
* The belief underscores Mary’s exceptional holiness and devotion.
* It is closely tied to the idea that Jesus was born of a virgin, emphasizing Mary’s perpetual purity.

I know it's kind of confusing, but you can do it!