Blog posts disappeared from homepage

Hey everyone,

Im having a big of trouble with my blog posts. There seems to be a gap on the homepage of my blog http://www.probablybest.co between 4th October – 18th October. They just seemed to disappear from the homepage one day. The posts are still there though and can be found here :

http://www.probablybest.co/2012/10/us-presidents-as-brands/
http://www.probablybest.co/2012/10/365-days-of-tumblr/
http://www.probablybest.co/2012/10/miniature-worlds-by-catherine-nelson/

Ive had a look at the settings and cant figure out why they would all of a sudden disappear from the homepage?

Thanks,
Megan