Congrats, mama! Team boy na kayo, how exciting! Don't worry na ang slight difference between LMP and ultrasound dating (16w5d vs 18w), yan normal lang, especially kung irregular periods ka or conception timing wasn't exact, so doc will usually go with the ultrasound date na mas accurate talaga. Enjoy this moment ng finding out, and hayaan mo na ang slight dating confusion, what matters is baby boy is on his way!