Are you looking on the amended refund lookup? Amended returns can only be mailed. It can take them 16 weeks for the IRS to process them. And they only mail checks for refunds. After 3 weeks you can track it here, <a rel="nofollow" target="_blank" href="https://www.irs.gov/filing/individuals/amended-returns-form-1040-x-/wheres-my-amended-return-1">https://www.irs.gov/filing/individuals/amended-returns-form-1040-x-/wheres-my-amended-return-1</a>
By "sent them in", I'll assume you printed, signed, and mailed the forms yourself. TurboTax does not mail it for you.
Normally when mailing things to the IRS or state tax agency, it's a good idea to use a method that has tracking such as certified return receipt, priority mail, etc. Then you have proof of mailing as well as knowing if/when it was received.
ADDENDUM: See VolvoGirl's comment and link posted above to be sure you are using the correct tracking tool at the IRS website. The amended return tracking uses a different one than an original return.
If you still can't get info with that one, then you can phone the IRS to see if they can check another way to see if it shows on their system. Here's how to reach a live agent.
IRS: 800-829-1040 hours 7 AM - 7 PM local time Mon-Fri
Listen to each menu before making the selection.
First choose your language. Press 1 for English.