I also didn't do as well as I hoped today. I only slept a couple of hours the night before, so I was tired and a bit sick during the test.
I answered all questions though (guessed what I didn't know ...), and I can think of two technical mistakes now, after a little nap. There was at least 1 incomplete Q, I'd have guessed that hard Q, except time ran out. Another one is I never clicked "save" button for my essays, I wonder if they recorded and still submitted full essays, hopefully not blanks, since there wasn't submit button. I finally typing right before the little window popped up.
I think I only got a composite in the low 20's. Hopefully not 20 or 19 or 18. If I can sign up and take one in another month, I know my true potential is 30-33 on a perfect test day. How'd raising 10 points in a month a or two look to med schools? They forgive my 1st bad one?
There's 2-day rule, and to OP, I think even late reg. deadline passed for 4/17