Will taking a pass/fail STEM class make me seem bad

Im a soph. There is a Bio class exam that I did not do well on and it seems the highest I can get is a B-. Will switching the course to P/F affect how admissions view my transcript. For context, I got As in my previous 2 Bio classes. Also my school requires that another main STEM subject be pass/fail bc they havent changed requirements since COVID but Bio has the letter option.

This would be my 3rd B in just the beginning of my 2nd year. Please let me know the best move. Would just a pass for this one be bad?