Hello~
I am 11 weeks and can feel the occasional flutters (or butterflies) since two days ago. From what I look up, movement is usually that feeling, and sometimes can be mistaken for hunger.
I felt really small movements at about 16-17 weeks. But I was always like I'm not sure if that's just gas or the baby. Then between 18 and 19 I could really feel him kicking. Now I'm 23 weeks and you can see it, even if I have a shirt on. He kicked me last night and I had a cup of hot tea resting on my stomach and it spilled on me.. I couldn't even be mad I was just like ow! Holy crap! Lol
And honestly the earliest you will be feeling real 'flutters' and not just gas or something else is at least 16 weeks, unless you have previously had a child. So if you still haven't felt anything by 20 weeks or so, then you could worry.