What is this big dip? Dang.

Lynda
Today is 7dpo. I'm seeing this big BBT dip and losing hope for this cycle. If AF on her way or could it be a implantation dip? I've read that implantation dips are only for a day and then shoot back up, so probably AF. Also I had a small amount of spotting yesterday day after DTD. So many theories, I can't keep up. Thoughts?