Could it be leukemia symptoms ?

My son has had a lot of health problems lately, but the doctors usually tell me that it is either all in his head or he is faking it. I finally took him to a doctor that is very concerned and wants to send him to Primary Childrens Hospital in SLC. He is 12 years old. He will come home from school and take a 4 hour nap, he gets a lot of muscle and joint pain, especially in his legs, he also gets right upper abdominal pain, he bleeds and bruises easily, rectal bleeding with no known cause even after colonoscopy at age 10, now he has started to develop bruising on his fingertips like you would see with a diabetic that has to constantly check their blood. The bruising on his fingertips just showed up yesterday while he was writing in school. He has lost weight, his appetite has decreased yet there are days he can't get filled up but then he is sick. He gets frequent nose bleeds, and a lot of infections. It seems that all he has to do is look at someone with a cold from across the room and he has one.

He is 1/2 mexican so it is hard to tell when he is pale. He has had bruises on his legs for nearly 12 years. His white blood cell count was high. He has had scarlet fever and meningitis when he was about 3. They never did a spinal tap but treated him for meningitis. I am very concerned and wonder if this could be leukemia from all of the symptoms he has had. Our family has both downwinders from Uranium mines as well as the fallout in Nevada. I have lost all but my uncle from my dads side from cancer because they lived near the Uranium mines. They moved away before my uncle was ever conceived. He got lucky I guess.