There should be a word for the moment just before you get butterflies. When you are a bit on edge, knowing something's about to happen. When there's a bit of something in your fingertips and starting your mouth twitching towards a grin, but it hasn't reached your stomach yet. When you don't know which way it's going to go. When you're scared, but half the fear is being scared you're about to be happy. When all it takes is one thought or one word and then you're fluttering again.
What would be a good word for that?