Im experiencing an unusual sensation in my upper chest when walking. It sounds like there is water slopping around in there. And when i say sound other people can actually here ir. Its not painful, although you can feel a slight jarring sensation as it slops against the side of whatever it hits.I am a mild asthmatic and bronchitis but very mild
It could be slight accumulation of fluids, but you have not reported fever etc. I would suggest to better get it excluded at Pulmonologist.