Suggest Remedy For Swelling And Infection Due To An Injury

This is for a kid 8 yrs old.He injured himself on Monday. No bleeding. Area is swollen.and is soft to touch.yellow feeling when s touched. Looks like pus is formed. No significant pain to the kid in that area though. Area around is blue too.shown to doctor on Friday. He is taking now augmentin 325 till Monday morning which is 3 days treatment. I still saw the same yellow pulpy felling on the main injury impact area. Can u pls advise if this medicine is right course.for many days this treatment should continue, do we have to cut or take out the pus, risks , dangers in this etc..thanks