I have leukemia, is it more likely that a bacterial infection become septic?

It is possible. Leukemia itself may reduce your white blood cells that fight infection (granulocytes) but many of the treatments we use to destroy these leukemia cells also reduce your normal granulocytes. This can increase your chance of infection and spread to the blood stream (sepsis). Antibiotics offer some protection from this happening.
No. Leukemis is blood cancer, depending on the type, u need treatment urgently, there are many type of leukemia. Some need treatment right away, but some can be observed and treat later or may never need. M.