See if there is a record of your return being Accepted or Rejected,
https://turbotax.intuit.com/tax-tools/efile-status-lookup/
That is only for efiled returns. If you printed and mailed it won't show up there.
Check your account. It's common to end up with multiple accounts. First LOG OUT of whatever TurboTax account you're logged into right now. Then use this TurboTax account recovery website to get a list of user ID's for an email address. Run the tool against any email addresses you may have used
https://myturbotax.intuit.com/account-recovery/
If you used the Desktop CD/Download program then the only copy is on your computer and not saved or stored online.