Will my freshman & sophomore year grades put me at a huge disadvantage?

<p>I got a B+ both semesters in my Honors Algebra 2 class freshman year, and then a B in my Anatomy & Physiology class sophomore year (first semester), and a B in my precalculus class (first semester. I'm in my junior year now, and I've gotten all As (upward progression and all) and I'm working a lot harder, so I think I'll have all As through the rest of high school, and my the time I graduate, I'll have taken 11 APs. Right now, I have a 32 ACT and I'm aiming for a 34 by the end of the year. My extracurriculars are pretty solid, I founded/am the president of a chapter of an organization that sponsors girls' education in developing countries, am looking into running for other positions in clubs like HOSA and Science Olympiad for senior year, I also run varsity track. I've been playing the viola for 5 years and am in a youth symphony. I also write a blog and have done some work with film. Some schools that I'm interested in are University of Michigan (I'm in state) and Tufts, and I'm interested in the premed track. Chance me? </p>