I assume you physically mailed the Form 1040X and associated changed forms yourself. TurboTax does not mail it for you.
It can take the IRS up to 16 weeks to process an amended return. How long has it been?
Does your amended return show up in this IRS tool? It should show up in the tool about 3 weeks after you mailed it.
https://www.irs.gov/filing/wheres-my-amended-return
