I was 100 dollars short today

I've been off on my drawer before but I can't help but stress out. I found out I was 100 dollars short at around 1pm today, we're one teller short so I didn't print out my balance and decided to start over after helping the customers. I go on break, come back, and didn't have time to balance again until around 4, since we we're short staffed and with it being Friday. I realized I actually am short 100 dollars but was too scared to tell the manager, but we also were really busy. I know i messed up by not telling her immediately, but I know she would've found out anyways because we need an override to close our drawer and we need to put our closing ticket on her desk. (She usually leaves at 5pm and we leave at 5:30) has anyone ever gotten fired for being short that much? I'm seriously stressing out and worried I could get fired. When I called a supervisor for an override, she didn't seem upset or anything but she's not the boss from my branch specifically. I don't know what else to do but rant about it on here :')