You've done the work to clean up your credit score, scrape together a down payment and pry a pre-approval letter from your mortgage lender. Cheers!
Getting preapproved is a smart move, especially in a seller's market characterized by tight inventories and, in some regions, bidding wars. Having a lender's letter in hand signals to sellers that you're a legit buyer whose offer merits serious consideration.
Even so, a pre-approval letter is just a conditional commitment. It can be withdrawn if your financial situation changes in a way that makes your lender nervous.