Crazy A$$ Period

Obviously since its Friday most of us are off to school or work. For me that's school. I get through English, and biology fine and I'm feeling pretty good about today, until I get to gym. At this point in the day I've had a super tampon in for about 2 hours. One typically lasts me 4-5 hours so the thought of changing doesn't cross my mind. Towards the end of gym I feel a huge gush in my pants. Right, so I keep jogging, even thought internally, I'm screaming. Get into the locker room, go to the bathroom and boom. MASSIVE blood stain that went through my shorts.... I sorta just sit there for a minute and think about how unusual this is. I barely had the tampon in for 2 hours and it looks like somebody got murdered in my underwear.... Fast forward and hour or two and here I am, home early from school because I bled myself.... 

Has something like this ever happened to anyone else? Like, your periods are usually okay, then all of a sudden it turns into a nightmare?