How to get over this embarrassing moment?

i am 12 years old and Yesterday the people across the street from my house had a yard sale. I had on a short skirt and really tight underwear. It was the 3rd day of my period so i was wearing a pad. I went over to a big counter of stuff. And then i guess that the sides of my underwear snapped because it was on the ground. I didn't even notice, but other people did. A bunch of teenagers started laughing at me. I asked them what was so funny but they wouldn't tell me so i just ignored them. I noticed other people snickering at me and i couldn't figure out what was wrong. Then these two hot guys tapped my on the shoulder and told me to look at the ground. To my horror i saw polka-dotted underwear with a dirty pad, and there was blood running down my leg. I shreiked and started running towards my house when i realized i left the underwear, so i ran back and got it, my face bright red, and ran into my house. Totaly humiliating. A bunch of people who live on my street and who i see everyday were there! How do i get over this???