Considering that there are MD med schools that don't evaluate individual subscores and that your numbers are collectively decent, I'm not convinced you need to retake the MCAT to get an MD acceptance (assuming comprehensive ECs, supportive LORs, and good interview skills). Instead, you'd need to make some phone calls to find out what school policies are when evaluating an MCAT score and if they have a minimum for VS (if not apparent from the website). While you're at it, also ask how they evaluate multiple MCAT scores (do they use an average, the highest, the most recent, etc).
If you aspire to more-selective MD schools, particularly those that post subscore cutoffs, then retake, but try to move your timeline up by 2 months. If you feel the first VS was a fluke, you shouldn't need 3 months to study for it.
If you do decide to retake, making the future date known on the AMCAS application is likely to be in your better interests.
If your ECs aren't strong enough to help adcomms overlook at subpar VS, then you might consider taking the MCAT in September as you'd planned and waiting until summer 2015 to apply.