As cookderosa points out, a science degree with no lab credits would be a bad idea if you're trying to get into medical school.
I'd suggest completing your current TESC degree and then taking a second BS in biology or chemistry at a B&M college. Most B&M schools will allow you to transfer a huge chunk of credits from the first undergrad degree (standard is 90 credits out of 120 required), so you'd only need to concentrate on the hardcore science classes.
I would also, like cookderosa, advise against taking the bio and chem CLEP. They'd be duplicate credit and worse, they'd be entirely inadequate for the major.
The University of Maryland's pre-health advising department considers the following courses necessary for those desiring to attend med school:
Chemistry I & II
Organic Chemistry I & II
Physics I & II
Calculus I & II
All but calculus would require lab sections. They also strongly advise microbiology, genetics, biochemistry, and physiology. You'd be taking those courses during med school, so they recommend taking the undergrad versions to give you a strong head start as well as give you a big edge on the MCATs.
Check out the forums at Studentdoctor.net. There are message boards for pre-med students, including one for what they call non-traditional applicants. There are also message area for residents and practicing physicians - read through all the angst surrounding the match process (med school seniors apply for residencies, get invited to interviews, rank the residencies by preference, and then wait to see if any residency wants them - there is NO guarantee that you will land a residency after med school).
Not to scare you off the idea, but there's a long road ahead if you want to be a physician!
BSLS Excelsior College, conferred 9-09
started MS in Instructional Design program, Spring 2010
April 4 2009 through July 6 2009: 1 GRE subject exam + 1 Penn Foster credit + 11 DANTES exams = 61 credits. Average per-credit cost = $23.44.
"Nobody can go back and start a new beginning, but anyone can start today and make a new ending." (Maria Robinson)