I m taking an antiviral Aciclovir for my Shingles. My doctor says my case looks fairly mild and we re hoping to have caught it fairly early. I have occasional stabbing pain in my arm and only four clusters of bumps which haven t changed in the last 48 hours since I started the antiviral. I am however today feeling headachy and tired. I have read that this could be side effects of the pills as much as the shingles itself. Is that possible?