I was diagnosed with aml 3 yrs ago ,i am healthy now. what are my chances of a relapse?

Talk to hematologist: Your long-term outlook depends on a number of factors including your age and prior general health. The most important factors are the genetic characteristics of the abnormal myeloid cells. Your hematologist has or can obtain detailed information about the genetics of the disease. There is no guarantee; you will need continued surveillance.

Possible but unlikel: The prognosis for AML depends on many factors, most important being age: patients under 50 years of age do fairly well, but the outcome is not that good for those over 60 years of age. Since you are healthy now(I assume you are in complete remission(CR), there is less than 50% risk of relapse. The risk will further decrease with each passing year....relapses are rare after 5 years in CR.