So it is definitely not too late for interviews. I didn't get any until mid september, and my latest was in Janurary, just becuase you haven't heard anything yet doesn't mean anything. Now, as far as boosting your chances I would recommend applying to a broad range of schools. Certainly all your state schools, and then schools that have average stats close to yours. Also, consider at least 20 schools, if not more. It is expensive but your stats on are the lower end of competetive, so more schools are your friend.
If you don't get in this cycle you ahve a couple options. One more year of classes/ a MBS program can raise your grades. Retaking the MCAT is risky. It depends on if you truly think you can do better the second time. If you are very confident that you can go up by atleast 2-3 points I would go for it, as the difference between 31 and 33/34 is significant I think. Finally, if your EC's are lacking in clinical experience or research then you should have time to get that added for the next cycle.
Overall I think you have a decent shot this cycle as long as you have a broad and large range of schools. Worst case scenario you have a strong base to work on to make yourself a great applicant next time around.