First session of IPL didn't produce coffee grounds/any results...

...it was done by an MD and the PA that works for the laser manufacturer. I spoke with the MD and told her there were no results and she said that they weren't very conservative and the laser was set to the proper setting. She said they can be more aggressive next time. This concerns me. Do we then run the risk of burning? And if the laser was set to the proper setting, does this mean my skin reacted in a unpredictable manner, and being more aggressive next time is shooting in the dark? Thank you