Ephiz,
Protein in your urine is a potentially serious condition called proteinuria. Your case of lupus is attacking your kidneys and it would be wise to see a nephrologist who will probably want to do a kidney biopsy to assess how much damage has been done to your kidneys. Proteinuria is usually easily treatable with an ace inhibitor like lisinopril.
I had it and after treatment (which will continue forever) my kidneys were and still are functioning perfectly.
Do not ignore these symptoms. Your cold or whatever has nothing to do with your kidney condition. You can wait until you feel better but see a nephrologist and get the biopsy if he deems it necessary.
Bill