Her immaculate conception in the womb of her mother, by normal sexual intercourse, should not be confused with the doctrine of the virginal conception of her son Jesus.The immaculate conception refers to the fact that She was born immaculate (without stain or sin) and our Holy Mary is therefore doubly immaculate, both at Her own birth as well as when She gave birth to Jesus while still remaining a Virgin.
I am conducting an informal survey today to see how many Catholics actually know this fact and, so far, 100% of the sample has confirmed how widespread the misconception of the immaculate conception really is. Amazing! Thanks Steve!