When do you think is the best time?

I recently had a discussion with my pre health advisor, and after realizing I would have most of pre-reqs by the end of the spring semester except biochemistry. She suggested I take it the MCAT in January? I am a sophomore and I plan on transitioning into med school immediately after undergrad. I will be taking biochemistry in the fall as well as anatomy(this is not required but recommended.) What do you guys think? Should I take it in January or wait till may? What are the pros&cons and any suggested study patterns?
My course load in the fall is as follows:
–> Analytical Chemistry
–> Biochemistry
–> Statistics
–> Anatomy & Physiology which is a total of 13 credits with 2 labs.
I also work as a general chemistry supplemental instruction leader for an average of about 10hrs/week.

I think Jan. of your junior year is perfect. If you schedule it for late Jan. you will have the entire break to study if you want, and should you should happen to do poorly, you will have time to do more prep/retake. Good luck.