Should I worry if I got 1 B on a class that isnt a prerequisites?

This may be a silly question but I've been stressing about my grade for biology. I ended the class with an 88% (B+ at my school) and its not really a requirement for the program im intending. I only needed to take it so I can begin Anatomy this summer. I so far have all A's in my actual prerequisites and the program does a point based system. So An A for Med term would be 3 points.

Would me having a B+ in bio still be bad for me? Although the program does point system, what if there is a tie and they need to go based on gpa? So far I have a 3.9 now but I heard so many people get in with 4.0 so im nervous that I messed up.

Did your school cared about non-required classes? Or am I just stressing for no reason?