Even though it's possible to efile now, the IRS hasn't opened up return processing yet this year, so the 24-48 hour clock hasn't started yet . The IRS opens up to start processing returns on January 27. If you efiled before then, your return will just sit on TurboTax servers until the IRS retrieves it on Jan. 27 (except for a few returns that are pulled early for testing purposes.) So you'll need to wait until January 27 (or soon after) to know if your return was accepted/rejected, unless it's pulled early.
NOTE: Even though you may be able to efile now, by law the IRS will not issue a refund on tax returns claiming the Earned Income Tax Credit or Additional Child Tax Credit until February 15 at the earliest.
I filed mine on January 28th and it is still pending. Should I be worried
Pending simply means that your e-filed return is on its way and that the government hasn't accepted or rejected it yet, sometimes it takes longer than 48 hours.
Here is more information: