Hi there! I have recently started to seriously track my BBT and have been reading a lot on charting and the patterns etc. I happened to look at my Fitbit today and noticed that a months heart rate seemed to follow the same pattern as a BBT cycle. A drop and rise in heart rate matches my believed ovulation days (haven't tried opk yet to confirm). I looked back over a year of Fitbit heart rate and every month seems to follow the same pattern. Has anyone else experienced this or looked into it? Some quick research I did online too suggests heart increases quite a lot with successful implantation so another possible cue?