I used the couch to 5K as well after reading a post advicing a novice runner to use it, I cannot believe how beneficial it proved to be.
I'm a (ahemmm) mid forty bloke that had never run since leaving school and even then i hated running with a passion, I really didn't think i had it in me but the Lovely Laura changed all that for me. I didn't complete it in the 10 weeks due to a couple of colds and injuries but i did complete it and i am now running a whisker less than 4 miles ( I don't do metric) every other day.
I actually look forward to my runs which is staggering considering how i felt previously, it really is all in the head, once you conquer your own self doubt you will be off and flying - or shuffling in my case.
Anyway, just do it at your own pace and if you feel your not ready for the next week then repeat the current week. It's about getting there, not how long it takes to get there.
Hope this helps any budding runners but i doubt it, just the ramblings of an old dud that is still questioning how it all happened.