Suggest Treatment For Ruptured Boil

I am undergoing chemo, and have developed a boil on my panty line. I have been using warm compresses, as well as peroxide and polysporin. I feel a bit weak, and my throat is a bit sore. The boil seems to have reduced in size from a nickel now to a dime, and does not appear to be infected. Two days ago, it opened and drained some pus. Do I need an antibiotic?