I'm hoping to submit my AMCAS application today in order to ensure it's processed by July 1 but there's one activity (future physician shadowing) that I'm not sure the exact number of hours I'll be doing- all I was told is 2-3 days. If I submit my application today to just one school (with an estimate of the amount of hours), can I change this information to be more accurate for later schools I add? What happens if I overestimate/understimate the amount of hours I'll be shadowing?