Selecting a birth control method is a complex healthcare decision. While
birth control methods provide important benefits, they can also cause
unpredictable side effects and be stigmatized, leading many people to seek
additional information online, where they can find reviews, advice, hypotheses,
and experiences of other birth control users. However, the relationships
between their healthcare concerns, sensemaking activities, and online settings
are not well understood. We gather texts about birth control shared on Twitter,
Reddit, and WebMD -- platforms with different affordances, moderation, and
audiences -- to study where and how birth control is discussed online. Using a
combination of topic modeling and hand annotation, we identify and characterize
the dominant sensemaking practices across these platforms, and we create
lexicons to draw comparisons across birth control methods and side effects. We
use these to measure variations from survey reports of side effect experiences
and method usage. Our findings characterize how online platforms are used to
make sense of difficult healthcare choices and highlight unmet needs of birth
control users