Inverted cross: If early Christians first used it…?

Many symbols have changed over the years, for example, the cross wasn't used until the 3rd or 4th centuries. The skull and crossbone was originally a Christian symbol of mortality and was often used on gravestones. The pentagram was not ociated with satanism or the occult until it was published in a little known book in the late 1700's and then was not widely known until Hollywood popularized it in the 50's and 60's. Prior to that it often symbolized the 5 wounds of Christ, the 5 knightly virtues or was used as a symbol of luck.