It's really hard for one to guess what it could be but I thought I would share what my boyfriend just went through. Well, basically what you are describing. He had a terrible cough, a fever, incredibly sore legs and a sore back. His whole body hurt like heck. Turns out it was just a really bad flu. He was given antibiotics and each day it got better. Initially, it did take a couple of days for him to start feeling better. But if you are that concerned I would call your doctor back. Take care and god luck. Kristy.
I had actually been thinking about that too, now that you mention it I have had sore legs for a couple days now too. I'm going to get the blood work done just in case.