Your best is always good enough regardless of the result. If you are doubting this, you are probably stressing about the expectations you have to meet or are a little disappointed... I feel you, which is why I am here to remind you (and myself- I see you future me) that you are perfectly capable. If for whatever reason, (because you are human and we all go wrong sometimes) you do not manage to meet what you were aiming for at some point- it is OKAY. It does not mean you are less worthy or less capable.