Hello doc,i did 2 elisa test 4th generation on 28 and 38 days post exposure..is it conclusive enough to say me as a hiv negative?

Almost conclusive: Almost certainly you do not have HIV; the tests you had are nearly 100% conclusive any time more than 28 days after the last possible exposure. However, on rare occasions the Ag/Ab (4th generation) blood tests take 6 weeks to turn positive. So if it was truly a high risk exposure and/or you would like further reassurance, have another test at that time.