I had an appointment at 1:00 PM on a Wednesday. I was the only person there for an interview so I was able to go to the first window right away. Paid for my visa and handed over all additional documents I brought to the interview. After that the lady asked me to take a seat and wait to be called up.
The officer said he didn't see anything alarming about our case and told me I could pick up the visa in 8 days.
The information on the embassy website for K-1 visa is rather misleading. Once they received my case they sent me an email telling me to schedule an appointment for the medical examination and fill out the DS-160. They do not tell you which documents you need to bring to the interview but make sure to follow K-1 visa guidelines on https://travel.state.gov/ and you will not have any issues.