How do I know my pull request will be (or has been) reviewed?

GitHub sends notifications to watchers of the repository when a pull request is created and when any comment is made on it. It does not send notifications if you push new commits so be sure to add a comment if you do so. By convention we wait one business day to merge to give interested parties a chance to review; see How do I review a pull request?.

Reviewers will explicitly leave a '+1' or '+2' comment meaning that your pull request looks good. A '+1' means another person must review before a merge is approved. The absence of a '+1' or '+2 implied that the pull request is not approved so if it's not clear why you should ask. Be aware that people usually give a '+1' or '+2' at the end of their review so give people some time to finish their review before assuming the '+1' or '+2' is being withheld.