Kristen Stewart didn't spend Valentine's Day with Robert Pattinson, but the Twilight actress doesn't appear to be brooding.

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Instead, the 23-year-old is focusing on herself. The already slim beauty is keeping an eye on her health with a new UP device by Jawbone, according to the Daily Mail.

The $150 bracelet connects to users smartphones and collects data on how the wearer sleeps, moves, and eats in order to help users make healthier choices. While UP has been spotted on Iron Man 3 star Gwyneth Paltrow, other celebrities can be seen donning similar devices by Nike and Fitbit.

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As Stewart headed into her first single Valentine's Day in four years, the actress acknowledged the fact that she is still too young to really know all this to know about love.

"You don't know who you will fall in love with. You just don't. You don't control it. Some people have certain things, like, 'That's what I'm going for,' and I have a subjective version of that," Stewart told Marie Claire. "I don't pressure myself ... If you fall in love with someone, you want to own them-but really, why would you want that? You want them to be what you love. I'm much too young to even have an answer for that question."

Pattinson, for his part, spent Valentine's Day abroad. The actor is currently filming for Queen of the Desert in Morocco.