I am taking plavix (clopidogrel) and i will have to add some aspirin for a month. i have erosive gastritis. what should i do?

All depends: The most important factor is why you are taking the Plavix (clopidogrel). Some indications such as peripheral artery disease may not be as strong as others, i.e.recent stroke. Erosive gastritis is a serious risk for bleeding; your doctor(s) will want to weight the benefit of Plavix (clopidogrel)/aspirin against the risk for you. Options include no anti-coagulation to other alternatives including heparin. Work with your doc!