Moms!! Movement or stretching?!

Rene
Im 17 weeks today and this is my first. The past week or so Ive been feeling what feels like my uterus being pushed from the inside. It's not consistent, but happens for a split second then occasionally again right after and when I feel it it's only in one spot. It doesn't feel like "flutters" that I've read other moms talk about. Could this be my baby? Or just my uterus stretching?