I Went To The ER On Saturday To Get A

I went to the ER on Saturday to get a boil lanced and it's infected and it has staff Mrs a and I put me on some Flexin 500 milligram every 6 hours and a bactrim medicine twice a day and they gave me some ointment when I went to my doctor after the ER but when I went to my doctor they said that it looks like it might need to be lanced again because you can feel like a golf ball up underneath it still so what should I expect when I go to the doctor tomorrow or will that work its way out with these strong antibiotics