Bleeding

I haven’t had regular periods since having my son a year ago, and my last period was three months ago. I’ve tested 3 times since then, and all have been negative. Two days ago I started my period and then yesterday the bleeding began to get darker and heavier than any period I’ve had in the past. I’m bleeding through every tampon i use within two hours and bleeding through pads in about 2-3 hours. I just woke up in a pool of blood even though i had on the biggest pad I own. Is this something to worry about? I’ve never been one to have bleeding like this. And I’m nervous there’s something else happening.