WanabeDR,
Don't worry about it. I was as happy as I could be to get a B in ANY of my classes. I actually made a couple of D's along the way. One was in Posterior Segment Disease Management and One was in Vision Therapy. I didn't care about Vision therapy then or now but I think making a bad grade in Post. seg made me work much harder to learn it. Ironically today I have a largely ocular disease practice.
I know it is easy to say don't worry after you have already graduated. But just do your best. You NOT going to get kick out for making a B (or even a C or D). And I PROMISE, NO ONE will ever ask you what your grades were after you graduate. At least they haven't asked me. Not an employer nor a patient. Grades are pretty much for you own personal enjoyment (or horror).
A's, B's, C's (and not too many D's) make an OD.