Should I put bad grades on my resume?

I had a 3.8/4.0 GPA out of my target undergrad school, but I was a social sciences major. Now I'm about to start a masters in finance program at a semi-target school and I have already slipped in my summer class which just released the final grade. I received a miserable B for this 3-credit financial concepts class because I was working full-time over the summer and I had little to none prior finance experience, and now I think I'm screwed. 

I spoke with an academic advisor from our school's career center, who told me students typically start looking for jobs right after program begins (late August). Now I already have a B on my transcript, I'm wondering if I should put it on my resume or not? I know I can always improve my GPA by working harder and getting A's on other classes but our program is only one-year-long and the job search timeline is really tight. Am I already totally screwed? Any advice would be greatly appreciated.