How to tell the difference?

I am a first time mommy to a 8 week old baby girl. She uses a pacifier to get her to sleep. Here's the problem. When she wakes at night, im not sure whether she is whinging for her pacifier coz she has woken to find it not in her mouth or whether she is hungry? She doesn't cry, just makes little noises and moves her head around like she is trying to find her pacifier. If i get up and put it back in her mouth she will go back to sleep for another few hours at least. What do you think this sounds like? wanting her pacifier or food?