My fitness tracker knew I was pregnant before I did

Ravika was on a birthday vacation with her husband when her smart ring sent her a strange alert. The Oura ring said her health score was poor, even though she felt perfectly fine. Her heart rate had gone up, her body temperature was higher than normal, and a reading called heart rate variability had dropped. It turned out her fitness tracker may have noticed something big before she did — she was pregnant.

A week later, Ravika's stats still hadn't improved. She is a 34-year-old lawyer from the West Midlands in England. She went online and found a group of women who said their fitness trackers had been showing possible signs of pregnancy before they even took a test. About a week after that, Ravika took a pregnancy test — and it came back positive.

Soon after, she felt some cramping and got a notification on her phone saying her body appeared to be under serious strain. She went to the doctor, who told her to come back 10 days later to find out if the pregnancy was healthy. Those 10 days were incredibly hard to get through. Ravika found herself waking up at 4 a.m. just to check her app. She said the data became an obsession because it felt like a life or death situation.

For most women, the first sign of pregnancy is a missed period. That is also around the time when a pregnancy test can detect a change in hormones. But Ravika is one of hundreds of women who say they saw early signs in their fitness tracker data — even before their period was late. A 2026 survey found that 36% of adults in the United Kingdom owned and used a fitness tracker — almost twice as many as in 2019.

One of the earliest signs of pregnancy is a change in body temperature. During a normal monthly cycle, a woman's temperature rises and then drops just before her period begins. But in early pregnancy, the temperature usually stays high. Fitness trackers that measure body temperature can detect this pattern and flag it as something unusual. This is why many women who are trying to get pregnant find these devices helpful.

Sofia, 32, also noticed signs of pregnancy — and miscarriage — through her Oura ring data. She lost two pregnancies before having a healthy baby boy who is now five months old. One morning, she saw her temperature had dropped in the app and knew something was wrong. When she did miscarry, she said she felt already mentally prepared because of the data she had seen.

Three months later, the same thing happened again. Sofia and her husband decided to take a break from trying to get pregnant, but during that break her ring sent a strain alert and her temperature was high again. She took a test, and it was positive. Even though the pregnancy was healthy, Sofia kept waking up at 4 or 5 a.m. to check her temperature reading. By seven or eight weeks pregnant, the stress became too much, and she took the ring off for the rest of her first trimester.

Dr. Stuart Lavery, a reproductive medicine doctor at University College Hospital in London, said it makes sense that people want to use this technology to learn about their health as early as possible. But he warned that without enough research on how reliable these devices really are, people's anxiety could skyrocket. He said fitness trackers and apps should come with a big health warning about how much people can trust them.

Oura's clinical director of women's health, Dr. Chris Curry, said pregnancy can be stressful and uncertain even without a fitness tracker. She said the company encourages users who feel overwhelmed to take a break from the app. She also reminded users that the ring is a support tool, not a replacement for a medical care team.

Sadly, Ravika did have a miscarriage. She hopes to try to get pregnant again soon, but her experience has changed how she thinks about her tracker. She said that if she suspected she was pregnant again and her stats were low, she would take the ring off as soon as she got a positive pregnancy test — because for her, that would be the healthiest choice.