Lucy,
The grade point average section of the AMCAS application divides the gpa into 7 sections:
Freshman
Sophomore
Junior
Senior
Post-Bac
Undergraduate (combined from categories above)
Graduate
Your 2.9 will be distributed through your freshman, sophomore, junior, and senior years. Your 3.7 will go into the post-bac section. I don't know how many units you took for your BS in Biology or your post-bac courses, but I'm sure your undergraduate gpa will be above 3.0. Since you demonstrated your ability to perform in the prereqs now, I suggest you go to graduate school. I have 2 options for you. If your science gpa is pretty high, I suggest you do an M.P.H. If your science gpa needs some improving, get an M.S. For the M.S., I suggest going to a program where you can take classes with med students (ie. Georgetown SMP, Finch, Drexel, etc...).