Doctor said i have acid reflux. so when i run for about a minute i tend to gag, is this an acid reflux symptom?

Hard to say: Make an effort to avoid any caffeine or nicotine products, eating or drinking any significant volume before you run. Your core will tense during a run & provide pressure on your stomach. If you have reflux & tend to backwash stomach acid/contents these changes can avoid aggravating the symptoms. I can see where this might be an issue, but related symptoms are often difficult to pin down.