Pregnant.....or not.....?

Well gurls...I got a BFN this morning and I am soooo upset....my fiance' and I were really hoping for 2 lines instead of one......AF is due today no later than Mon......still queasy......metal mouth...no cramps or bleeding.....sore .....so..when should I test again or shall we just try for a christmas baby......send lots of BABY DUST PLEASE.......