Six days of watery nose and congestion despite your current combination, plus new chills, a feverish feeling and now stomach upset, suggests either a secondary infection or your body still working through the original illness. This is a bit longer than a typical cold.
Next Steps
Go ahead with the CBC and
CRP your doctor already advised, since those will show if a bacterial infection has set in. Keep up fluids, rest and light food for the stomach upset.
Health Tips
See your doctor again sooner if the fever rises, breathing feels tight, or the stomach symptoms worsen.