Popping in pelvis and belly?!

I'm 38 weeks and I keep hearing and feeling pops in my pelvis that AREN'T ME. Like I know it's obviously my baby, the pops aren't painful but they do make me nervous since I didnt have this in previous pregnancies. It sounds like knuckles cracking in there!!

I dont have any leaking, and I just had an ultrasound and they said my fluid was perfect so i dont think it's anything drastic as they likely would have seen it today at his growth scan.

Has anyone else felt or had this happen? Like there are times he kicks and pops my back but this popping isn't my bones because I cant feel it necessarily, I just hear it when he moves. It's so freaky!!!!