Weeks 20 days 4.

Hi mommies, please enlighten me. I have yet to feel my twins kicking. However i do feel bubbles and flutters at times. May i know is it normal for a 1st time mum to be? Or could it be because my stomach is thick so i could not feel the kick? Worried. They say i should be able to feel my babies kicking already at this time. #pleasehelp #firsttimemom