My boyfriend's parents did NOT like me the first time they met me (and I didn't care for them either). But you know what? He still liked me. Don't be nervous -- you already won him over. That was the hard part.
Michelle, they are most likely just as nervous about meeting you too! You are going to do great--just be yourself and they will love you for it.
I know just how you feel. DH and I just met our DD22's BF's parents yesterday at DD22's college graduation. I was so nervous and they came to our house afterward for a small celebration. It worked out great they are really down to earth, nice people. I know that Bf's mom was just as nervous as I was!