Suggest Treatment For Pus-filled Pimple Around Healing Wound

I believe I may have the beginnings of a staph infection/a small staph infection. My friend recently came down with a staph infection, and I believe it might have spread to me. He is currently on antibiotics. I have a 2 inch healed wound that is red on my upper right arm. I thought it was completely healed and didn't think that it could still catch staph. Yesterday my friend noticed a small pus pimple on the outer corner of my wound. We washed all my clothing and sheets and put a bandage on it. When I took a shower the pimple popped and now the site only looks red and feels tender. My friend has an antibiotic ointment specifically made for the staph infection. Should I just make sure everything is clean, use the ointment and cover it with a bandage unless I notice the injury worsen? Do you feel it is imperitive that I go to the doctor for antibiotics? I do not have much money to afford going to the doctor repetedly or afford much in the way of anitibiotics, and I am not near a free clinic. Thank you.