I'm not really sure if you will ever know. I'm thinking you need to look up the requirements on the application process to schools. Does it say you are not allowed a conviction or an arrest? Your fingerprints are on file because of the arrest, so are easily traced (altho this is an expensive & time consuming process & probably not done on every applicant). If it is only a conviction - my advice would be to not say anything on the application & try not to worry (easier said than done!).
Once you are actually in pharmacy school, it is usually no problem. I had a classmate who was convicted of a drug charge (this was in the 70's - lots of drugs...) He had to go before the Board to explain before he was allowed to take the exam - would probably be done now by letter. But..he was allowed to take the exam & later worked for the Haight-Ashbury Free Medical Clinic (treats lots of drug abusers), but this is CA - different than Wisconsin.
Hopefully, you'll be able to explain. Perhaps those who have been through the application process recently will give you more insight. Good luck!