Bled through at school- Help!

Today is my heaviest period day, and I changed my pad two hours ago, and I bled through everything. Oh god. I'm on the school bus home and I'm freaking out. 
I get off in ten minutes... oh my god I am going to die. The bus is full of people and other people get off at my stop. I have my backpack and laptop bag with me. No jacket I can take off. Help me please?