Over the last couple of weeks (I am 24 weeks) I have noticed what I can only describe as a fizzy or bubbling sensation around the right side of my ribcage. It seems to only happen when I am sitting upright, at my desk for example. It stops when I put my hand on it, and is not painful at all, but is a bit irritating. Anyone else have this? Or know what it is? I don't think it is the baby moving, as that feels quite different.