I agree with Robert. And...You need to be asking your attorney these questions. If the house was sold at auction on 4/9, and they let you stay there til 4/23? that sounds pretty nice to me. Many buyers (like investors) aren't so nice and could have put you on the street that day, or worse. You no longer owned that home and were essentially tresspassing.
Robert is right on...Recording with the county can take weeks. That has no reflection on when the property actually changed ownership.
And yes, you are still responsible for the HOA fees, trash, utilities, etc. that were being charged to you while you owned the home. If you had pursued a short sale, you could have had all of this negotiated.