What is this feeling?!


I'm 20 weeks 3 days and I have been getting this tightening feeling near my belly button. Almost as if baby is pushing or running his foot along my uterus I imagine? Like in the picture below.(this is obviously not my picture) I'm a plus size girl so if this is what I'm feeling I can't see baby push yet. My question is for those who have felt this feeling is it in fact baby pushing(like in the picture) or is it something else? I hope this makes sense! Thanks