Your chances at a DO school with your stats are probably good.
Your chances at US MD schools would be very low, even if you were not an international applicant. I'll assume there are no special circumstances present that might modify an adcomms view of your low stats. Your chances with those numbers and an application that is not complete until October would be nil.
Chances at a specific Caribbean school can be researched in SDN's international medicine forum.
Comments:
If you're interested, DO for Canadians SDN thread: http://forums.studentdoctor.net/showthread.php?t=739482
Taking vital signs is considered clinical experience rather than shadowing. Your shadowing is on the weak side, and it would be nice if you could shadow a DO.
It helps one's application if one has leadership, teaching, and/or nonmedical community service, too.
To find DO schools taking internationals: DO MSAR http://www.aacom.org/resources/bookstore/cib/Documents/2012cib/2012cib-whole.pdf