We all agree that Mary was a virgin the time Christ was born. What is missing from the creed that Im sure you would like to add is the ever virgin sinless queen of heaven. That stuff that Catholics made up later is rightly missing from the early creeds of orthodox Christianity.
https://aleteia.org/2013/10/10/a-protestant-defense-of-marys-perpetual-virginity/
Augustine, Jerome, etc.
Not in the creeds. Not necessary
Fear not...they have to believe that as well.
This is but one of the many things Roman Catholics have to believe to remain Roman Catholic.
Christianity and Roman Catholicism...there is a difference.