I know you can feel baby flutters at 15 weeks pregnant, but can a baby do this?

It was the baby. I had this happen around 15 weeks, too. I had to pee really bad, and right after I went I felt this shifting in my belly. I looked down and it was kind of poking out near my hip bone. I'm 33 weeks pregnant now and I know what a baby feels like. If it happened to me around 15 weeks, it probably happened to you, too. I am (was- haha) skinny, too. Maybe that has something to do with it.