My two cents: I, too, had weak undergraduate grades so before applying I decided to do a 1 yr postbacc that offered undergrad courses and grad courses. This was more of a favor to myself than to med schools because I really needed to make sure that I was solid in my sciences before pursuing the heavy workload in med school. The postbacc helped me retake some undergrad courses, and also introduced me to some grad science courses that ultimately helped boost my MCAT score tremendously. During that time I also volunteered heavily and got great LORs. I would reccommend that you look into a postbacc, get nothing but As, continue to volunteer, and get the highest MCAT score you are capable of. IF you dont get in this year, then you will surely improve your candidacy after doing such things.
Also, during my interview or First Friday ( I dont recall which one), they mentioned that Howard likes to strategically interview some students during a time that is most advantageous to the applicant, just as what freespiritb was explaining. So a late interview does not necessarily mean that you have a lower chance of acceptance. Just hold on tight! What I admire about this med school is that they are fair in reviewing a whole applicant in the context of their story and seeing their potential, especially when other schools are more concerned about the highest numbers to help move up their ranking.
And lastly, don't look too much to others for a source of hope or predict your chances. Your profile image describes having faith of a mustard seed; so pray, keep your faith and trust that it will all work out for your good in the end.