Gina, welcome to the current lending climate - scores, scores, scores (except government loans)... Let me explain.
Government financing (FHA, VA, USDA) have no credit score requirements (eventhough some lenders are requiring a minimum). Since the risk is not based upon your credit scores, a person with a 600 credit score would get the same as one with a 720.
Now... conventional loans have changed. Risk based pricing and mortgage insurance according to your credit socre. At a 680 or above you are safe. From 620 to 679, that's where the problems come in. Both in increased interest rates and higher mortgage insurance. For a more detailed explanation, contact your local lender or mortgage professional. These changes are happening NOW and across the nation.
A mortgage professional will lead you in the right direction.