Suggest Medication For An Infection In The Throat

I've had strep throat for 3 weeks now and have completed two antibiotic treatments of penecillin. My throat is not back to normal yet and I noticed something on the back of my throat that looks like a pocket of pus. I'm back on antibiotics but am concerned that it's not going to go away. Can this be a peritonsillar abscess that needs further treatment?