You don't say if your doctor is a urologist or not. If not, go to one. I am one, and I can tell you a significant number of men referred to me with testicular pain and epididymitis DO NOT have epididymitis. An ultrasound is useful but not definitive. I don't know your age but ciprofloxacin in younger people has been associated with spontaneous rupture of the achilles tendon( very rare but very bothersome). Is the skin of the scrotum red? Were you doing any unusual lifting before your symptoms? Do you have any urinary symptoms such as burning or discharge? If your doc is not a urologist get to one- I am not trying to scare you because this is very unlikely to be something serious, I just don't want you taking a bunch of antibiotics you may not need- I see that all the time.