If you are looking for all the posts you made hover over the groups tab and click my posts. I can see my posts all the back to september 2007. I know there are some before that but posts got lost in the change over to the new system in the last years. If you are looking for replies you have made to posts, you can hover over the groups tab and click my replies. You can get up to the last six weeks. The time frame for that page is the date the post was created not when you made the reply. So a post that has been up longer than that, say a guidelines post, wouldn't show. You used to be able to get them all but the data base was unstable and kept crashing. They now have this set up in place.
at 3:29 AM on Jun. 15, 2010