I started taking Cephalexin a few days ago after the urgent care doctor prescribed them to me for an infection. I've been having a lot of nausea from the drug, but I know it's not good to stop taking an antibiotic before finishing the full prescribed amount. Will the side effects last for the entire period of my taking them? Will the nausea eventually lessen or die off? I just want to know whether or not I need to go get some more Phenagren to make it through this!