What happens if you didn't put the medication you were taking on your school form?

On the school form my parents filled out, I told them I didn’t want to put my medication on there because it wasn’t a serious medication. And I didn’t want to reveal my sickness. Now I am trying out for sports, and I need to fill any medication. What do I do, and am I going to be in trouble? Also, please don’t say “You should’ve! It’s your fault.”.