A. Go to a clinic tomorrow (Sunday) and pretty much pay out-of-pocket for the visit, plus the cost of a prescription antibiotic that will probably knock the cough out in a couple of days.
B. Take an antibiotic you were prescribed for something else (that's since resolved itself).
ETA They aren't leftover. It's a whole new round that I never ended up taking. I mean, that you never ended up taking.
Which option would you choose?