Women have been manually tracking their cycles for centuries. You've likely heard the terms "rhythm method" or "natural family planning" from older generations; today, it's the more scientifically informed "fertility awareness." But as far as birth control options go, monitoring certain health cues to help women avoid getting pregnant still gets a bad rap—mostly because it's so subjective.

Fertility tracking has spawned a wide range of apps in recent years to help women better gather and track those cues, and they can work perfectly when done the right way—in fact, I used one of those apps to get pregnant. But, there's still a pretty large margin of error. Human error. All of the data is based on personal observation—collected by you, not a health care professional—and some of it needs to be extremely precise. Especially temperature, which measures a spike in progesterone, a key signal of ovulation.

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Now two companies have created devices to make tracking body temperature easier and more accurate for women monitoring their fertility.

A sample fertility tracking chart from Kindara, which shows the temperature data in blue

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Wink, by the company Kindara, and Ondo, by Ovatemp are the first basal thermometers designed specifically for fertility tracking which will record and sync the data instantly with your phone. (There are various Bluetooth-enabled thermometers that take your temperature by ear, which is not accurate enough for a basal reading.) They're both available now for pre-order: Wink at $79 and Ondo at $149.

Measuring what's called your "basal body temperature" gives you more precise data than you'll get from the old thermometer tucked in the back of your medicine cabinet, but it's also harder to accurately record. It means the lowest possible temperature your body is at for the day, basically the moment you wake up, which for many of us is not when we're at our mental best. Groggy eyes can accidentally mistake an 8 for a 0, and this can make a big difference when you're looking for changes in tenths-of-a-degree increments that could indicate a hormone spike.

Plus, to make sure you can see the necessary trends in the data, you need to take your temperature at the same time every day. If you oversleep an hour or two, your reading will be void for the day. By syncing up with your smartphone, Wink and Ondo claim to minimize the room for error.

But as excited as I wanted to be about the idea (and the fact that these companies are thinking hard about these issues), I'm not sure this is the fertility tracking solution we need.

Yes, these two devices might remove any of the errors that come from transferring the data from your thermometer to the phone itself. So maybe if you're really not a morning person, their effortless syncing would help? Or perhaps they could remind you to take your temperature, because your phone will act as an alarm clock to make sure you record your data at the same time each day. But I had a setting on my fertility app to remind me each morning to take my temperature, and that worked just fine for me.

I can't imagine spending extra money just for a thermometer that does one, very specific thing. It would be nice to be able to use it even when it's not connected to a phone (the Wink has a digital display for this purpose, but the Ondo does not). But even then you're just paying a ridiculous amount of money for a digital thermometer. (For comparison: I got pregnant by tracking with a $7.99 thermometer from Target.)

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Neither products have really nailed the idea from a design perspective either. Ondo's design is too much like a sterile, clinical thermometer which is also somehow like an old man's pipe, while Wink tries to disguise itself in a case that is meant to look like a tube of lipstick. This seems a little ridiculous; I don't think I ever needed to take my thermometer out in public or felt any need to hide the fact that I was taking my temperature in the morning. What's that? Oh it's just the lip gloss I stick in my mouth the moment I wake up.

We need something better. There have been recent calls by women for Apple to integrate a basal body temperature tracker as part of its HealthKit app. It's an intriguing thought: Someday, we ladies could have our temperature—as well as our other hormone levels—monitored by our Apple Watch or our Apple Earring, which wouldn't even have to wake us up to record any data with a separate device. It could track all our fertility signs for us, and maybe even give us a subtle nudge when it was a good time to have sex (or send a more dramatic notification when not to). A girl can dream.