believe it or not vs though

believe it or not

adv
  • This may be surprising, but it's true. 

though

adv
  • Despite that; however. 

  • Used to intensify statements or questions; indeed. 

conj
  • Despite the fact that; although. 

How often have the words believe it or not and though occurred in a corpus of books? (source: Google Ngram Viewer )