While having enabled two-step verification will have improved the security of your account it could be problematic if you have lost or don't have your device with the authenticator app to hand.
When you enabled two-step verification the last step - see step 13 in this guide - will have given you the opportunity to print or save a Recovery Code.
So, instead of entering the 6 digit verification code as part of the log in process you will need to click on the 'I can't use my authenticator app'.
Then you will be given the opportunity to log in using your Recovery code.
It is easy to check your current recovery code or generate a new recovery code.