Well, then I'd either suggest with sticking more or less with what you are doing for now - you are enjoying it, losing weight, getting fitter, and are injury free - you should continue to see steady progress for a while yet.
Or tweak your training & gradually lengthen one run, and shorten one run (but go harder - as a rough guide the kind of pace where you could grunt one or two words, but not have a full conversation - you should be able to keep the pace going for the whole run, and feel as if you have worked hard, but not be totally wiped out). If you want you could introduce a speedwork/interval session. A simple way to do this is if your watch has a countdown timer, set it to beep every 2 mins (or other interval). Run one of your usual routes, but go pretty hard until the watch beeps, jog recovery until it beeps again - repeat until you get home. Any other running should be steady and not too long. Changing to these more focused sessions should see faster improvements in time, but whilst some people relish the challenge etc. some find it takes the enjoyment out of going for a run.