Why isn't my Baby Moving?

I'm 37.5 weeks pregnant and my baby stopped moving about 3 days ago. I feel her maybe once or twice very infrequently compared to about 3-5 days ago when she still moved slightly but enough to feel. I know they move less as they grow, but now she rarely budges, kicks, flips, turns etc... yesterday I posted a question and everyone gave me ideas (drink OJ, something Sweet, put cold bag of ice on belly, etc...) I tried it all. I just had dinner and a can of sprite to see if she would move. its been 45 minutes and still nothing. The doctors yesterday did an Non Stress Test (NST) and everything was normal with her.... but when I asked what I should do when she doesn't move they said Drink something sweet- I was annoyed at this point and left... Now again today its the same thing NO MOVEMENT... what am I supposed to do? I have a scheduled NST tomorrow at noon... but should I be worried?