I was prescribed Macrobid for a UTI I didn't even know I had. I ...

I was prescribed Macrobid for a UTI I didn't even know I had. I toke my first dose on Sunday night, and woke up with severe flu like symptoms. I never call out sick at work. (once in 10 years) To day is Tuesday and I still feel so bad, extreme body aches, pains, dizziness, lack of energy, sneezzing, coughing, mucus, cannot sleep. I called my doctor immediately...my Dr. is on holiday, and no response from another physician. I am going to immediate care and stop taking Macrobid before hives and rash set in.