Do classes that are taken after undergrad count for your GPA?

I have the option of graduating early, either this Fall or next Winter quarter of my senior year (we're on a quarter system at my uni). I'm planning on prepping for/taking the MCAT and applying to med school in the months after I graduate. I'm also a nonscience major, and I want to improve my science GPA. But I really want to graduate early in order to save some serious tuition/housing money. I go to a really competitive undergrad, so it'll be much less stressful to take some upper-div sciences at another school, but I'm not sure whether this is a smart decision or not. Should I just stay for my whole senior year or try to graduate as soon as possible? Any advice would be greatly appreciated, thanks!

I had a cumulative 3.7 GPA and a 19 on the MCAT. One of my friends had a 2.9 GPA and a 20 on the MCAT. We are both in osteopathic med school. Something to keep in mind...

I think there are separate sections in the application for undergraduate and post-bacc GPA. I don't remember for sure.

If I were you, I'd probably invest the time and money now to bring up your GPA. Yes, people get in with low scores, but there is always the possibility that you won't. It is an incredibly arduous process, and I would not want to do it twice. Many people have to reapply.