How close to 400 are you?. My comsae was in the 370-380 for like 3 month. I did uworld, combank, usmlerx, my foundation were so bad those qbanks did not help me much. My only saving grace was OMM. Make sure you ace the OMM section, easy points, My highest comsae score was 405 (form B), that was 1 week before the exam, then I studied OMM hardcore, pass the exam with 415.