I've read in multiple places and heard from my doctor that it is completely normal to not even feel movements at all until at least week 22 so the fact that you're feeling movements is great!
Some of the ladies on my month board (March 2013) also just told another mom that it's completely normal to not feel regular daily movements until week 28.
I've been feeling movements for about two weeks now. Moreso over the last week. I feel movements on and off all day long. Sometimes it feels like a fish is rolling around in my belly and other times like popcorn popping. The kicks and jabs aren't very strong yet but they're there. I'm sure the day will come when I don't feel the baby move at all and I will panic as well. But I've been told by sooo many others that this is normal and fine.
I hope you start feeling movements more regularly from now on to help ease your mind!