Lopsided belly??? Advice pls

Hey everyone trying to figure out if this is baby girl or uterus??? The lump is sometimes on the right ( as of now on the right) and sometimes on the left. I’ll be 17 weeks tomorrow. Maybe I’m having Braxton Hicks and my uterus tightens and pushes baby up? I dunno lol I’ve seen a lot of people talk about how it’s the baby choosing sides. This is my first baby. What do y’all think?! My next appt is Wednesday so I’ll def be asking my doctor what they think as well!