If you're on the board index page, there's a link to 'view your posts' - towards the top right of the page, under 'View posts since last visit'. It'll show you everything you posted. I'm not sure if you can filter by forum, or by threads that you started etc. Maybe a mod can advise better?
Look up above and to your right for a link that says Search. Click on it. When that window opens up fill in the "Search for Keywords:" ...fill in what the name of your soap is. Then put in your username in the blank space underneath (Search for Author. Click search and it should bring up everything with the same soap name along with your username. Make sure that the characters are at least 4 letters long.