If you don't want to regret over your lost phone contacts, there is a need for regular backup. There are variety of ways to backup your phone contact.... You can backup it up to iCloud, MicroSD, using third party app etc.

However, when you misplaced your phone your MicroSD will definitely not find its way back to you unless you were able to regain access to the phone again.

With this, it is not recommended to backup your phone contacts to your memory card.

Meanwhile, there is a safe place I will admonished you to backup your phone contacts to... And that is to your Gmail account.

Literally, Gmail backup your phone email automatically once you have sync your Gmail account with your phone when loading your Android OS or afterward through settings.
So, I want to believe you have a Gmail account associated with your Android phone already.

Below is exactly how to backup your phone contacts to Gmail account.
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1. Go to your contacts list and select all your phone contacts.
2. Click on the ellipsis (3-dots) to the upper right and click on share.


3. A new window will popup. Click. Gmail from the lost of options on the new window that populates.


Fill the email form and click on send..... All you phone contacts will be forwarded to your email account in .vcf [vCard] extension.
You can view it on your computer and as well, restore it to a new phone.

Source: https://www.gadgetswright.com/google-contacts-backup