Help?

I'm 28 weeks & 6 days preggo. A few hours ago I started to have this weird like sensation in my upper right abdomen area Luke under my boob and it's not painful but just about every 10-20 minutes I have this weird I don't even know what to call it like a rumbling, a bubbling, cramping type thing and then stops. It's weird and I've never experienced this before. I don't believe it is gas related and I'm not constipated. Just not sure what to make of it. First time being pregnant can anyone help me understand?