No that is NOT usual to wait days to get results.
NDCA comps (which are usually several days long) will run a certain number of heats and then call out awards. Then run more heats and do awards. The big awards such as Top 25 student awards, Top teach awards, Top Studio award and scholarship awards are given out the last night at the banquet.
MOST one day comps hand students their placement sheets at the dinner banquet.
Who ever told you that you would automatically get 1st places because you are the only one in that heat in your level is dead wrong. You can STILL come in 3rd place, you have to be pretty bad, but it's possible - I have seen it! At my first comp I watch a smooth heat where an instructor moved his student like she was 2 foot 1 inch tall. Had horrible frame work, etc. I was embarrassed for her! He still teaches and wonders why he can not keep private students.
When you make a mistake on the comp floor take note and move on! It's always possible the judges didn't see it OR already turned in their judging sheets.
If your looking for fun, one day, non pressure competitions World Promotions is great fun. Look them up and find an event to attend. They do a lot of them here in the States.
You can also go over to the NDCA competition calendar and look at what's near you.
This is ALL public information that ANYONE can access. The only thing that is not public info is the price list. That your instructor has to call in for.
Glad you had fun!