Your smart ring or watch has many useful jobs, including learning your usual physiological patterns and showing you when they change.

Resting heart rate, heart rate variability (HRV), temperature, and breathing rate can all contribute to that picture, although each device interprets these measurements differently.

That works well until pregnancy changes what usual looks like for several of those metrics.

The first app I open every morning is Oura, so I know how much one score can shape my day. A low Readiness Score can make me feel like I've done something wrong, even when I haven't.…