Hi.... I am recovering from the flu . I went to a physician and got some antibiotics ( Z pack) which after a few days I m feeling much better BUT I m having lots of pain in my kidneys/ lower back now. Is there something else going on? I have no change or pain with urination . This is not a usual pain I have. I have been getting sick on and off all winter. Is this a normal flu symptom? Is there some ways I can treat this post-flu symptom at home? Thank you!