Yes, though it depends on how you are accessing the site. If you are on mobile, then the app doesn't currently have a way (that I'm aware of), though I would like to see it added. You can however, use a mobile browser to view the main site.
In both the current site and v3, you can view thing a couple of ways. On the current, v2, site, you can go to your home page and view content you started. On v3, you actually need to go to your profile, to see your Activity section.
For forum posts, both version have an option to view content. You can use the Topics I've Posted In and Topics I've Started options in v2 and in v3 you can use the My Topics option (which combines both of the v2 options).
Is there an easy way to keep tack of your posts and if anyone has replied? Thanks, Dean.