Check if it is first Login with G+ in Android

I'm building an android app, and i'm stuck with a feature that i want to implement at the login with google plus page. I implemented the activity and it works fine. But my problem is the following. I have a start activity and I want to check in this activity whether its the user first sign in or not? if it is i will direct him to the the login activity. if he already signed in i will just connect him in the onStart() and direct him to the main activity. Any clue how I can proceed.