When I log in, I just click on 'New Posts' (in the center, at the top) and it shows me all the new posts since I left.
I can usually remember, especially if it was something I posted (sorry, I know that's not incredibly useful to you)
You can also click on your own name, and then choose the option 'Find all posts by Lenniavy', and you see the list of posts you made, and I think that list is in chronological order (most recent on top).