What Causes Muscle Weakness And Chills After Starting Macrodantin?

I started taking Macrodatin for a UTI Friday at about 2pm. By 5pm I had muscle weakness, my skin hurt, pain, and chills. I did not have a fever. I spent the whole day in bed on Sat due to the pain. Today I have been up and around but the pain has traveled to my legs and arms. I read muscle weakness is a side effect of the drug. Is it possible I am having an allergic reaction to Macrodatin? Thanks, Kerrie