Muscle Spasm or Baby Moving?

I know this might be a ridiculous question since I'm only 12 weeks with my first baby but since yesterday when I'm laying it sitting absolutely still I've felt this odd feeling in my uterus area. It kinda feels like someone is very lightly running their finger across my tummy below my belly button but from the inside. I don't think it's possible to feel baby move this soon especially because I am a heavier set person & it is my first ever pregnancy but have any of you this early on? Almost wondering if it's just muscle spasms but I've never really had them in my tummy before... 🤔