As long as you have chemistry and at least one other Science/Maths course behind you, and get solid A/A* marks, Medicine or Vet Med is not out of your reach at all. Just take a look at each university's requirements incase they do want a specific subject in conjunction with Chemistry.
Tip - pick up a University prospectus and read the course description for every course. Think : does this interest/intrigue me, do I have the right A levels subjects/grades etc, would going to an Open Day and hearing more about any of these subjects help me choose?
You might be surprised how many courses/subjects don't need specific subjects - so you aren't limited to just 'maths/science' stuff. Law usually doesnt specify any subjects, and heaps of other courses in Social Science dont either. So look wider than your current A level subjects.