Am I pushing enough?

I'm afraid to overdo it and hurt myself but because of that I feel like maybe I am not pushing as hard as I should. I walked at full incline today for 30 minutes and did a distance of 1.15 miles. If I am running 1.5 miles in 30 minutes that means at a full incline I am almost walking as fast as I am running. Now that I have the console working I will better be able to judge my running speed so hopefully I won't feel so pathetic but I don't know that I am actually pushing myself hard enough when running.