experienced mommies help?

Question for mommies who know the drill..
I'm a ftm and I'm currently 21 weeks 1 day and am wondering what is a normal amount of movement to feel in these next upcoming weeks. ? 
I can feel my baby girl when I'm resting and or have eaten or drank something but not much really beyond those times (random jabs here and there) 
Should I be feeling her move all the time ? Or is it normal to only feel her when I'm resting? 
My doctor hasn't told me anything about this and of course I'm always feeling that I should feel more, and worrying that something could be wrong. 
Any and all feedback appreciated and welcome :) 
Thank you guys!