Once the IRS has accepted your return, it then goes into processing status until they review and approve your return. The IRS Where's My Refund site has the most up-to-date information regarding the status of your return, so you will want to keep checking. The IRS updates the Where's My Refund site once a day, usually in the overnight hours.
Please see the IRS Tax Season Refund Frequently Asked Questions for more information on the refund process.