Category Count in a title

I want to add a category count next to each page title on my blog. It is kind of hard to explain. But if you look at my blog: http://pennybookspublishing.com/

at the top there are 3 tabs: home, about me, and books published. I want to add a category count to each letter. Does anyone know if this is able to be done. Thanks, I know this may have been worded weirdly and a little confusing.