My Son Has To Go To A Hemotologist Due To

my son has to go to a hemotologist due to his lab results being off....he was supposed to get his tonsils and adnoids out but his doctor wouldnt clear him until they ran more tests.... his mch and mcv was pretty low. and his rbc was a little bit high not much but a little.. his doctor wouldnt give me any more information she said she didnt want to scare me. he doesnt have any symptoms of anemia. the kids is never fatigued and i think in his whole life (which he is 7) he has had mayb 2 bruises and he plays really rough. but i do know he always complains about his belly hurting. they ran tests for that about a year ago and said everything came back fine including his blood work....so can this be just a mishap from the lab? or what could possibly be wrong since i can seem to get straight answers before his appt.?