I Was Recently Diagnosed With Strep Throat - Very Sore

I was recently diagnosed with strep throat - very sore throat, chills or cold sweats, body ache, headache, and mild cough - and was given a shot of penniclin 5 days ago. About a day or two later my throat felt much better but I still suffer from all the other symptoms, and I'm feeling fatigued as well. Is this the lasting signs if the strep or is something else going on?