If I do undergrad school in less than or equal to three years, will it affect my med school chances?

Answered

The short answer is that you will not be penalized for applying to medical school with 3 years of undergraduate studies as long as you graduate with a Baccalaureate degree and have all the other check boxes ticked. I think the best medical schools like Harvard require you to do 3 years undergraduate work so just lose that idea of applying with 2.5 years of college if you are applying to top Medical schools.

The long answer given that you will not be penalized is more nuanced and complicated. I have a number of reasons why you wouldn't want to do this.

1.) If you attend lesser colleges not Ivys, Elites or near-Ivys for the sake of saving money or getting full credit for your AP course, that's commendable and your parents will high five you. Mind you, part of this assumption is that undergrad colleges like Harvard, Brown, Yale, MIT, don't give much AP Credit and only if you have 5s. But IMO, you lose the benefit of getting the highest caliber undergraduate education and experience on campus that has intrinsic value that is easily not quantifiable. Some top Med schools might look past the MCAT stats and prefer a certain class, caliber or character of students. This is not dissimilar to Ivys recruiting from Top Boarding schools like HADES (Hotchkiss, Andover, Deerfield, Exeter, St.Pauls). But then again, this is only an opinion. If being a great doctor was purely technical, I'd zip it, but I think that being a great doctor requires someone to evolve into the best version of themselves , not just have the mental ability to perform research, or specialize or have the technical mastery.

2.) If you want to save time and money there are other ways to "skin the cat" so to speak. If money is a barrier, then try to get into UCLA on scholarship or Cornell in NYC where all 4 years of Medical school is Free. If you want to cut the time by a year, then apply directly into a BS/MD program at Brown, Boston University, where you do 7 years and get an MD instead of 8. CV has a list of the top 25 in the US.

https://blog.collegevine.com/admissions-heros-top-25-combined-bsmd-programs/

3.) Back to college debt, I think's its important to re-examine what different colleges will cost using a NPC Net Price Calculator for a variety of schools that offer pre-med programs. IMO, I feel that the hardest private universities are positively correlated to provide the most financial aid regardless of what income bracket your parents fall into while State school do not. So even if your parents make 6 figures, getting into say a Top 40 Private college that meets 100% of financial need will be cheaper than attending a good state university system. If you haven't evaluated all the best premed schools this way, I highly recommend doing it. You will be surprised that the sticker price is not the price your parents may pay.

4.) It is obvious to me that you are highly ambitious and are loading up on the AP Smorgasbord like other high achieving HS students. Like yourself, I will have taken nearly a dozen AP exams before I graduate plus 2 college course and 6 dual enrollment college courses. But where our goals diverge has to do with how I want to evolve during my early adult years from age 18 when I start college to 21 when I'm supposed to graduate. I feel that most of us who take care of our mortal coil will live into our 80s, possibly our 90s if we don't abuse ourselves and live healthy clean lifestyles. Therefore unlike you, I'm not rush to be a "thing" or a "profession". I'm going to college for different reasons. I want to learn how to think better, write better, gain more self confidence, be a better orator, acquire unique sets of knowledge that aren't available now, meet interesting people and teachers and mentors, and belong to all sorts of groups that interest me. I haven't had a normal full 11th grade nor a 12th grade so I miss the social aspects of school and look forward to taking my time to grow into the person I'm supposed to be.

Whatever you decide, I'm sure it will be the right path for you. Best of luck.