Rounding final grade

I just took a final for one of my classes and got my results back it it actually dropped me .5% :((( (I was never good at science). I was at a flat out 90% and now I’m at 89.5%. I don’t know if I should email my professor asking him if there’s any chance to round up my grade but this will be my first B and I don’t want to taint my GPA. I know it’s not the end of the world but I just don’t know how to go about this whole business.