Heart rate while pregnant

Kathleen • MMC 9.24.17 MMC 01.12.18 Rainbow Baby Girl 03.08.19

Has anyone been keeping track of their resting heart rate while pregnant? I'm 8 weeks today and it's been going down for the past week, after steadily increasing. I'm so nervous it's a sign of miscarriage as I've had two already. I keep reading different things saying it's not normal or it's not normal and I would love to hear people's personal experiences.