Implantation Questions

I noticed some of you ladies have talked about an implantation dip in your bbt chart. I just received a thermometer and started checking every morning about a week ago. Today, I noticed a dip in my chart (see pic), and I know it could be implantation or my period. Im 7 DPO, so iy could easily be either one.

Im not having any cramps or spotting, and when i checked my CM this morning, there wasn't any blood (today is suppose to be the start of my period, but my cycles can be irregular)

Could implantation still be happening?