When I received a certain book this morning ( Book A) I cane in the house and accidently reported that I had received a different book ( Book B).  When I realized my mistake I did report that I received Book A but do I have any way of changing what I reported about Book B.? Of course I can just wait until it comes and everything will be groovy. But that makes me a little nervous because it is already a week late.

I don't know the answer to your question but you could send a message to your tour guide or go to live help and ask one of them.

I don't think there's anything that can be done.  A book can't be unmarked as received.  This might just a lesson to learn.  Also if it was still in your Enroute To Me tab then the book wasnt late. If it had gone lost then you would have had to go into your Transaction Archive to mark it received.  A book isn't late until the date PBS marks it lost.

I did that once, so I sent a pm to the sender and told her what I did and I would pm her again when I got it.  It worked out. 

From the Help Center:

I accidentally marked a book received!

Once you mark a book as received there is no way to undo this action.  The software simply doesn't "go backward" in that way.  

• When you did this, the sender got credit for sending the book.
• You can contact the sender to discuss this if you want.  To do this:
  • Go to your Transaction Archive page under My Account in the toolbar at the top of the site
  • Scroll down to see the completed transaction for this book on the Transaction Archive page
  • Click to send a message to this sender
    • If the sender does not respond within a week, please let us know

If you marked a book received with a problem and there was not a problem with the book, you can change the swap status as described in Follow-up on Problem swaps.  Doing this will not "un-mark" the book received, but it will remove the "problem" mark from the completed transaction.

If you marked a book received accidentally from the En Route to Me tab in My Account:

• This book was marked mailed; chances are that it will arrive.
• Please wait for your book; most likely it will arrive and you will have already marked it as received, and won't have to do anything further.
• Please try to be very careful about which books you mark received.