If I were you, I'd plan to re-take it because there is no way you can get into a Medical School with lower than a C in a pre-req course. Plus, in order to have credit for it for medical school from your university you probably need either a C- or C so you'll need to re-take it anyway. If you re-take and get an A and then take a higher level Chem course you'd probably be able to prove yourself as capable.
MD schools will average your 2 grades for the class together and DO schools will only count your most recent.
Not to mention one F can kill your overall and BCPM GPA...seriously.
I was failing o-chem 3 last year, but I dropped it 4 weeks in, got a W, retook during the summer and pulled an A-(quarter system). If I can do it you can do it.
However, let me tell you my attitude and work ethic was drastically different the second go around.
(if you do what I did there will be no affect on your GPA)