I received my stimulus 1/29 but filed on 1/23 that I had not. This won't be filed until 2/12. Can I still amend on TurboTax? If not, do I cut it up, cash it or?

No, don't cut it up.  You can cash your check and spend the money.  The IRS originally said that it would stop issuing stimulus payments on January 15.

 

But it is continuing to issue payments and will now stop on February 5.  This situation is happening to a lot of people.  

 

If your return should be rejected when the IRS opens on February 12, then you can correct your taxes and resubmit.  

 

But if your taxes are accepted, the IRS will have a procedure to resolve this.  We do not yet know what they will do.  If they do need confirmation from you, they will notify you.