Early decision

Vassar is my first choice and so I was planning on applying early decision 1 to Vassar College. First quarter grades close at my school in a week and the early decision application is due in two weeks. Unfortunately, I recently did very badly on a calculus test and my average is 77%. I have pretty good standardized test scores, but I don’t think I can get my grade above 80%. Is it worth it to even apply early decision or should I get my grades up during the second quarter and wait for early decision 2? If I drop the class, will it look bad on my application to not take a math class senior year?