Heavy flow

Hey guys, I got my period about 3 days ago. The flow was normal until I woke up this morning and honestly, I was terrified. There was SO much blood. When I got out of bed gravity had forced a lot of the blood down my legs. In the last hour and a half I have needed to change about 10 times because I have bled through. I have a tampon and a pad for extra protection and it doesn't seem to be enough. My flow is definitely heavier than normal. Any ideas as to why that would be the case?