Before I took the test I told myself if I got under a 30 I would retake.
What score were you expecting?
Were you doing better on practice exams?
A 28 is not a bad score, and if I were you I would apply.
That being said, if you have the time and you really want this, I would think about taking it again. 28 is below the national matriculation average and although you have a shot at any school, your chances increase with a better score.
Studying for the mcat takes perseverance...
Medical school is going to take perseverance...
Being a doctor is going to take perseverance.