Stitching together monthly average graphs so you can see all my data at once:
I was struck by the drop at the end of 2018!
But I knew there was a major event that probably explains it: I gave birth on December 26th 2018. (Also lost 20lbs / 9kg in the space of a month. And I had gestational diabetes that went away. A big physiological shift.)
It looks like this is “known” – from this paper, “During pregnancy, the mean maternal heart rate usually increases by an average of 10 to 20 beats per minute” (note: referencing another paper that isn’t as easily accessible). So… totally normal and expected, but I learned something new.