If you are without your phone for some reason, you should call your admin.
Think of today's lost phone is yesterday's forgotten password. When you forgot your password, you called the helpdesk for to make the necessary arrangements for access.
If you lose, misplace, or forget your phone, your admin will issue you a temporary access method (e.g. recovery PIN, smartphone, security token, or smart card depending on your policy). If truly lost, your admin will also revoke any access associated with the lost device.
Forgetting, misplacing, and losing a phone has shown to be less common than losing your wallet. But, be safe!