Dorothy - I'd call the doctor that prescribed the antibiotics first thing in the morning and ask about it. Unless it continues in quantity today, in which case I'd be calling today!
Seems several have asked about this on the internet, but I can't find where anyone has answered.
Acute sinus infection
In addition to nasal congestion, expect to see discolored mucus (yellow, green, or occasionally more delightful colors. Brilliant orange, that was my personal favorite), facial pain, facial pressure, and an overall crappy feeling (malaise). Fever is uncommon in adults. http://boogerz.blogspot.com/2006/09/when-is-it-more-than-cold.html
Miller, Exactly my concern. I remember reading about infections in the nose affecting the brain. That's something I wouldn't fool with on my own without a doctor's diagnosis.