The advice I got when I was a 3rd year was to schedule it so that the results come back after transcripts go out (check with your school). Basically, I took it at the end of September, transcripts went out 2 weeks later, then my CK score came back 2 weeks after that. I choose NOT to automatically resend my scores in myERAs, so I didn't have to worry about my step 2 scores. Anyway, if your score comes back and its higher than your step 1, you can select to manually retransmit the score. If its lower, don't!
I ended up scoring higher and I resent them, which I'm sure made the programs I applied to happy. I ended up matching were I wanted.
Good luck to all.