Fitbit HR & ovulation

Rebecca✨ • 29,FTM to my 2 year old daughter && coffee-obsessed!
I've noticed over the past few days or so that my resting heart rate has risen according to my Fitbit. I am in the middle of my fertile window and was just wondering if any of y'all have noticed something similar? It is too early for me to test for a BFP (period started June 19).