Apologies in advance if I sound like a drama queen 
About an our ago I started to get a strange sensation in behind my sternum - it sounds/feels like popping candy. I've also noticed that I'm breathing through my mouth more, as I don't feel like I'm getting enough oxygen in breathing through my nose. Coughing a bit, to shift something on chest as well. Apart from that feel ok in myself. Could it be the start of a chest infection?