hi, i went to a doctor because i had what appeared to be a rash on the back of my neck she then told me that i have herpes zoster , that was almost 1 week ago, but i started medications about 4 days ago, im taking acyclovir Oral, but now the pimples got bigger, their color changed a little, theyre yellowish greenish, and they look like a big bump, but they feel much dryer then before, is that normal? should i go back to the doctor?