Oh Nikki, hopefully you'll feel the baby soon. I only started feeling the flutters at the end of last week, so at 17.5 weeks. This morning is the most I've felt in one go, at 18+1. Hopefully you'll feel something when you hit 18 wks.
It really is a flutter, like someone doing flips in there. Occasionally I feel something a little stronger that feels more like a kick, which for me is like alittle bubble popping against my tummy.