I've already published all my content before setting that up, so does that mean it not work and I'll have to start over again?
I've already published all my content before setting that up, so does that mean it not work and I'll have to start over again?
Not at all mate, no. Just click the 'Check' link near the update button in your post if you make any changes and the plugin will do its job checking once again. Honestly, install it whenever you want. It's a cracking little plugin to be fair.