DH: Dear Husband (or Designated Hitter, for the un-hitched)
BD: Baby Dancing (making love)
EW: Egg White consistency CM (the good stuff!)
HCG: Human Chorionic Gonadotrophin (Pregnancy hormone detected by HPT)
AF: Aunt Flo (your period, in other words)
NT: No Text (the title contains all the info - no additional information in the message)
Her dog Spot: Spotting that accompanies AF
ROTFLH: Rolling On The Floor Laughing Hysterically