Mine started feeling like gas and then started to feel like a twitch I felt him at like 22 weeks
This is my first and I didn't feel that bubbly feeling till about 22 weeks but if it's your second then you could be feeling movement:)
I'm not sure about kicking but I'm 18 Weeks and feel the same bubbly feeling. Today I could actually see my stomach move when I felt the bubbles. I know it's baby moving but can't tell of its kicking or just shifting positions. It's a great feeling though.