Can I review your contract?
Professional wedding photographers have a contract. That document is designed to explain your rights and what you can expect from your photographer, especially what recourse you have if something goes wrong. The contract also specifies what you are getting for your investment. A photographer that has taken the time to work up a contract has already thought through these things and wants to make sure that you know what to expect. They are professionals who care about the customer.
I spent a lot of time thinking about my customers when I was setting up my contract. I wanted to make sure that I was explicit about meeting their expectations and that the contract was fair and reasonable to both sides.
Doing business on a handshake is a rare thing these days. I believe that the contract says a lot about the people that you are doing business with. Your investment in wedding photography is not insignificant. Your photographer should take it seriously.