Ginger Beer. first time. help.

[cecropia]

i am making a ginger beer concoction from the recipe in wild fermentation and had a few questions. after bottling into some glass bottles i filled a plastic bottle with the ginger beer solution so i could tell how carbonated the beverage was getting. its now three days later and i notice cloudy formations appearing in the ginger beer (it kinda looks like kombucha, spent yeast cells) is this something i should be worried about? also, instead of carbonating and the bottle becoming fuller, i observed the bottle had actually concaved and lost pressure. what does this mean? any help would be greatly appreciated. thanks-Stephen