Wahey;
There are some liberal Protestants who believe that there were actually at least 16 Apostles, including four women - Susanna, Joanna, Mary of Magdala and Mary the mother of James.
The basis for this idea is Luke 8:1-3, which mentions that they (along with some other unnamed women) were always with Jesus along with the 12, and Luke 24:1-11, which shows that they were among the women who attempted to anoint Jesus body in the tomb when they discovered that it was empty.
There are at least two ways we know that they weren’t counted as Apostles, however. First, and most glaringly, none of the Gospel writers ever include them - they are constantly referring to “the twelve” - as far as the Gospel writers are concerned, these women were faithful disciples, but they were never Apostles.
Second, there is nothing anywhere in Christian Tradition to indicate that they themselves ever thought they were Apostles.
The fact that the Gospel writers never thought that they were, and the fact that they themselves never thought that they were, seems to indicate that they never actually were.