hi pink_lynne,
i'd say go for the park run too, you know you can do 5k,
and in the mean time personally i'd repeat the weeks before week 9,
where you have different run lengths back up to week 9,
aiming to increase speed,
you could also keep running when laura says you've made it, which would add another 5+ mins to your run, then do cool down walk.
this is what i planned to do, before got injured, and after i'd completed a 5k event i was going to do a programme which took me from 5k to 10k.
i found one on bupa website, but of course there are many.
i have also been told of the following one, which i havent yet looked at:
http://blog.bluefinapps.com/about-bridge-to-10k
good luck