Chart Help?!

Kristen • 💑 6/11/11 💍12/9/17 👼May 2018 • 👼November 2018 • TTC #1

7dpo.. ive charted a few months now and Ive never had a dip and pike around 6-7dpo. My temps always just stay the same and then drop for AF. Could this be a sign?!