You can always get to your own postings by going to your home node and clicking on the number of postings and then selecting from the resulting list.

The exception to this are posts to the Categorized Q&A section (but not replies to those posts), which actually end up being owned by the Q&A Editors so they don't show up in your list (though they do get added into the total). If a node of yours gets deleted, then all bets are off (whether or not you can get to it from you list of nodes or whether your count of nodes gets updated seems to vary at least a little bit).