Vibrating uterus

KP • Mama of two DD 04/14 and DS 03/16. #3 and last due 3/19
I can't remember if I had this with my dd but I'm 6 weeks 3 days now and for the past couple days I've had the sensation of vibrations or like a humming in my uterus. Anyone else having this sensation? It's kind of annoying lol