duchenne dmd cpk level

Hi, We need some help, Our son was a premi. Born at 32 weeks. He has some delays in his activities. He didn't start to sit by him self until about 8months old, He is 16 months old now and walks with assistance. He is starting to pull him self up but has difficulty some times doing it.He is in therapy once a week for his weekness. We had blood work done on him and the first cpk level was 18000. the second was 15000 and the lates was 11000. If he has duchennes will the cpk levels drop??? We have gotten many different opinons. we are waiting on the go ahead from our insurance to get the genetic testing. When he walks he looks like a typical toddler to me. But he is our only child. We keep reading he should be walking by 18 months. Is that walking on his own??? or with assistance by 18 months. When i say assistance i meen by holding his hands. He will walk if i hold one hand, But he really feels more comfortable if i hold both hands. He will walk around the house holding onto the wall with out getting tired. He will stand own his own for a few seconds but then he wants to either grab something or sit down. I understand that some boys are very lazy, and that is what we are praying for. If any body can help us out until we get the testing done we would appreciate it very much.