IMPLANTATION BLEEDING?

Hey girls. I need your help. About 5 days ago I started spotting blood which didnt get heavy till later that night. Then for the next four days I had a pretty consistant flow, except it wasnt as heavy as my normal period. My pads were taking a longer time to fill up (I used about 3 a day), however, when i used a pantyliner I kept having to change it every 3 hours or so. The blood was red, not pink or brown discharge. However, it was a few days before my period was due. Overall it laster 5 days when my period usually last 6 or 7. Do you think its implantation bleeding or are my periods being irregular? If anyone has any imformation on implantation bleeding please let met know. Thank you.