Sign Language Miracle

That day in clinic, came a young couple, age in early 20's, came for urine pregnancy test.Me: Your wife..(looking at her kinda strange name)Guy: My girlfriend actually..ya she's a Thai.Me: I see..hmm may i know when's her first day of last menstrual period (LMP)?Guy: (frowned) This is difficult..Me: Difficult? (i thought difficult to remember)Guy: Err hard to ask la..we actually have some