40 minutes to walk 3 miles

I just started walking today to make the c25k a little easier on me being over weight.

A lot of people are talking about how exciting it was that they ran for 30 minutes and got 3 miles, and don't get me wrong that is AWESOME! I wish I could run it. lol

Is it possible that my aim to run 3 miles in 30 minutes is setting the bar too low for myself? because I feel that if i jogged the whole time I would make it. :/