If you have not completed the filing process of the return through TurboTax, you do not need to do anything else. Your return has not been sent to the IRS and you can go to another tax service. If you decide to come back to TurboTax and complete your return the return will be as you left it.
However, you have gone through the complete filing process including payment to TurboTax you cannot file the return again through another tax service.