Come on now. PK is so 20th century. Those of us who used to be PK's are now TO's (or Theological Offspring), the more policitally correct 21st century term. That way all of the PK's, MK's, and what have you are all grouped under the TO banner.
PK, MK, TO. It doesn't matter. Just remember we're all rotten. Or at least that's what I've always heard.
PK (or TO) since 1955 and proud of it.