This is a tough call, as the transfer process is quite selective. Out of the 516 transfer applicants this year, less than four percent were accepted. This continues a trend of ever increasing selectivity that can be seen across higher education.
Your 3.9GPA is quite competitive, but with acceptance rates this low, it becomes much more than numbers. Surely much more than four percent of the applicants were qualified to be admitted.
I believe that Amherst, along with others, are looking to admit students of unique experiences and backgrounds that will contribute to the Amherst learning experience. So I suggest considering what sets you apart, what you care about, what makes you tick, and building your application around that concept. With the three application essays (one-commonapp; two-supplement), you have an amazing opportunity to illustrate who you are.
Hope that helped