If I went tanning this morning, and my chemical peel is scheduled in five days, should I hold off?

Tanning causes skin damage so I would recommend that you not tan and wait until the skin heals before considering a peel.
Tanning, which damages your skin and a chemical peel to try to improve your skin are incongruous.
Good luck.

Tanning is not good preparation for a chemical peel as you will have a thicker keratin layer to remove and may not get great results.  Your tan will be removed in the process and as a result the skin tone may be more uneven and a line of demarcation may show where the peel was stopped.  I suggest calling your doctor and discussing a good pre and post treatment plan.