Depending on the way you fork a github project, the remote source for git push and git pull may still be set to the original project, for example if working in a local git client, or attempting to change a cloned project to your own fork for development.

But, no sense guessing, you can easily find out. To see where your git repo is sending its 'push' and 'pull' calls, use this command

view plain print about
1$ git remote show origin

which should show something like this, with the organization and

view plain print about
1* remote origin
2 Fetch URL: https://github.com/[original username]/[repository].git
3 Push URL: https://github.com/[original username]/[repository].git
4 HEAD branch: develop
5 ...

Worth noting you can use

view plain print about
1$ git remote show
to see the list of available remotes, usually 'origin' and 'upstream'

To change the github origin so it points at your own fork of a repository, you can use this command to change the username (github organization name), so it points at your own fork of a project

view plain print about
1$ git remote set-url origin --push git@github.com:[your username]/[repository]

running this again should show your fork as the origin source

view plain print about
1$ git remote show origin

Note: by leaving the "pull url" to the original repository, you can easily sync your fork with the original by using

view plain print about
1$ git pull
which will pull from the source.

But having changed your origin --push , anytime you use

view plain print about
1$ git push
you'll be pushing the commits to your own remote fork on github.com