I don't think you're late. But for now, just ace your courses because your clinical experiences are probably fine for med school. You won't need to take the MCAT until you're done with your core courses (bio, general chem, organic chem, physics) so just sit tight about that for a while.
I would also suggest talking to a pre-med advisor at your university. You'll be able to get good advice about what courses you should take and in what sequence.
Good luck!