should I apply to oxbridge medicine ??

I got 999998877 in my GCSES but I think theyre too low considering oxbridge shortlist using those and BMAT so I'm a bit worried about that...
my predicted grades are A*A*A* and ive been doing loads of supercurriculars like EPQ, two essay competitions, and loads of book, articles and magazine reading - do I have a chance of getting an interview ??

Oxford do not shortlist using GCSEs anymore and only consider them for those not making the initial shortlist as a second pass. Cambridge consider GCSEs in context holistically with the rest of your application. Note though that to make a competitive application to Cambridge you really need to be taking 3 STEM subjects at A-level, as those not taking 3 STEM subjects are far less likely to be successful in applying.

Bear in mind that going to Oxford or Cambridge will not directly affect your medical career in terms of progression, as specialty recruitment is blinded to your medical school to ensure there is no bias based on where you studied your medical degree, and foundation post placement is done by algorithm and doesn't factor your medical school at all. So there's no specific reason to apply there, especially if you aren't confident you will get an interview, unless there is a specific element of the course that appeals to you.

yh I do maths bio chem at a level - are you sure Oxford don't use GCSES to shortlist anymore ???