I'm 18+2 with second baby and I am just now really starting to feel her move.. I have felt the flutters since 13 weeks but now I actually feel kicks and movement.. but I usually only feel her at night unless I sit up and wait patiently lol.. I wouldnt worry to much, my sis just had her third baby and didn't feel her till almost 24 weeks..
Some baby's don't kick very hard. Could be just that. My mom said she rarely ever felt me kick