Baby ๐Ÿ‘ถ๐Ÿผ or gas ๐Ÿ’จ

Sarah
Would anyone of you decribe the "flutters" as a rapid sinking feeling in lower abdomen? 19+3 and still trying to figure out if it's the baby or gas :( 
Especially, when I lie on my stomach, I get this sinking feeling in my lower abdomen.