Bleeding

Hi everyone, I had a question. So I started bleeding a little over a week early. It's also very light compared to normal. In 4 days I've used maybe 3 pads and there was barely anything on them. Was wondering if it's possible implantation bleeding? Also very moody and light cramps normally I don't have cramps and my period is very regular and very heavy flow. Normally I have to change pads every 2 hrs and they are completely full.