I'm taking 1000mg Amoxicillin twice a day (12hrs) for bronchitis. Having chills and stomach is uneasy, are these normal side effects?

Maybe. chills is not a medication side effect, suggest more an issue with infection. The upset stomach may be tested to your medication. If you don't have diarrhea or vomiting and can tolerate the abx continue for now. You are on full dose . Take some light food. If things don't get better contact your MD.