question: Hi! I ve had what the doc thinks is an infection under the armpit. It was a sore lump (another appeared soon after) and I was put on a 7 day course of antibiotics. The name I m not sure, butnit had penicillin in. On the 6th day I had really bad diarrhea (one of the prescribed symptoms) as well as small stomach cramps. I also developed a swollen vien..thread like. I went to the doc on the 7th day and he told me not to take the last 2 antibiotics. The swollen vein like thread is still under my armpit and om a bit nervous. Can ypu shed any light on things?