Period flow?

So I have a question about my period. I have had 4 kids...abd my tube are tied. So I can not be pregnant. Okay, now that's out of the way, my question is: what does it mean if your going through a super plus pad every hour or so? My period just kind of abruptly started 2 days early. It was 5 days early last month. Any ideas? Please let me know. Thank you!