I've never heard of a medical student graduating in 3 years on their own, the only cases I have heard of are students who apply and are accepted into formal 3 year programs that are specifically designed for that and those programs usually result in classes starting earlier, no summer break between 1st and 2nd year and I believe a lot of them don't require going through the match process. NYU for example, part of getting accepted into the 3 year pathway is that you get accepted into a slot in their residency program at the affiliated hospital.
So if your school does not have one of those programs that condenses everything in this way, then I can't imagine how you would graduate that fast.