Your creatinine is only just outside the normal range and may be perfectly normal for you, particularly if you are well-muscled. If it just stays at the same level, there probably isn't a problem. The test is used to indicate kidney function so if levels start rising from your normal level, it could indicate a problem with the kidney.
Slightly low leukocyte count could be caused by e.g. a recent virus or antibiotic use. Again, if it's only just under the normal range, it's unlikely to be a problem unless it starts dropping.
Low haemoglobin can be due to a number of factors, your GP will do various investigations to rule out anything untoward