You can send in secondaries as late as before Thanksgiving if you're a decent applicant, though the recommended time frame is August - October.
Someone correct me if I'm wrong, but I think you can submit your primary application (without MCAT scores) in order to get verified by AACOMAS. People do this by simply applying to a throwaway school. Then when you receive your scores in August, you can send your scores to the schools and apply right away.... or you can decide to wait until the next cycle to retake MCAT, avoid risk of being a reapplicant, and then give it your best shot for your target schools.