How can you view your private activity in github?
click on your name, in the top right banner.
Let me revert that: you are right.. only public activity
Ok, found it... Login, then look at the page. 2nd top banner: News feed/Your actions/Pull request/...
You can use the GitHub API to get access to your own private activity feed.
https://developer.github.com/v3/activity/feeds/