Did you prepare two returns for the same tax year in the same online account? If so, that overwrites the first one. Each Federal return needs a separate account, separate User ID, and (if applicable) a separate fee. If it turns out you did overwrite the return, you can download a free tax return transcript from the IRS website.
But first, check to be sure you don't have multiple accounts without realizing it. You may have filed it in another account. To get a list of your User IDs and recover account access, you can use the tool at the link below. If you have more than 1 email address, you should run the tool on each one.
NOTE: Before running the tool, log out of all Intuit accounts including this user forum, or you might end up in a loop. Then clear your browser Internet cache, close your browser, then reopen it, and go to the link below. You may wish to copy this link so you can paste it into the new browser session.
If still no luck after running that on each email address you have, then run the tool yet again, but this time choose the small blue link that says "I don't know my email address or User ID", and it will look you up by SSN and other parameters.