I'm assuming you mean credit union? I would suggest that something is wrong here. It is almost unheard of to put an offer on a home without a pre-approval and in some cases, it is not allowed. Well.... let me elaborate on this. The term "pre-approval" is so often used when, in fact, what we mean is a pre-qualification. However, either way, I think you need to talk with the supervisor. I personally do not know of any agent that will spend time with a buyer without knowing whether or not they can actually afford to buy the home.
Your lender should be able to give you a preliminary pre-qualification or pre-approval based on credit scores and what you tell them. Then this document will sometimes qualify with certain conditions that need to be met. If you need a good lender, I work with several honest hardworking lenders that would be happy to do this for you.
If you are interested, email me and I'll forward their information on to you.
Best of luck in your house hunting.