I'd just make sure I'd describe the issue to the desk when making the appointment - hopefully it's nothing too horribly serious, but I think I'd like them to get me in ASAP. Actually, knowing me, I'd be calling for an appointment from their parking lot!
Maybe write down any symptoms you or your girlfriend have noticed - headshaking, pawing at the ear, responding, or not, to sounds....any little thing may aid the vet with diagnosis and treatment. Good luck, and let us know what the vet says. Thanks!