Ginny Moyer weighs in with some great insight on BustedHalo.

Both Matthew and Luke make a point of explicitly stating Mary’s virginity. Some writers get more graphic: the early Christian text the Protoevangelium of James (around A.D. 150) includes a memorable scene where a woman physically verifies Mary’s virginity, right after Christ’s birth. Obviously, this text doesn’t have the authority of Scripture, but I mention it to show that early Christians were also interested in “proof” of Mary’s virginal state.

Read more to find out if other proof exists by clicking here.