This thesis explores fifteen women’s accounts of pregnancy over the course of gestation. It highlights the fluidity and dynamism of these women’s experiences, placing these in the context of the breadth of medical interventions they engaged with. Much existing literature concerning pregnancy focuses on specific instances of contact with medical professionals or technological interventions. This study explores the mundane and routine elements of the everyday practice of pregnancy, including during the first trimester. This is a period rarely addressed in academic literature. The thesis draws on data from in-depth interviews with women in Scotland, experiencing a continuing pregnancy for the first time. These were conducted at three points over the course of gestation. Interviews aimed to explore women’s interactions with medical interventions, their conceptualisations of the foetus, and changing experiences of embodiment. Analysis took place in several stages, incorporating three ‘readings’ of interviews and the development of a case study for each participant. This was inspired by the voice centred relational method of analysis. Themes were then identified and developed within, and between, individual women’s accounts. Participants’ narratives, particularly in early pregnancy, resonated with Rothman’s (1988) concept of the ‘tentative pregnancy’, originally developed to describe pregnancy in the wake of amniocentesis. Tentativeness emerged as a key theme characterising women’s experiences. Tentativeness was especially evident during the first trimester, largely due to women’s understanding that the risk of miscarriage was at its highest during this period. Women described managing their emotions at this time, in order to balance excitement about their wanted pregnancy with the possibility that it may end in a pregnancy loss. One aspect of this emotion work, explored in this thesis, was the effort made by women to keep their pregnancy a secret from wider family and friends for the first twelve weeks of gestation. Medical intervention and its associated technologies played a key role in both constructing pregnancy as tentative, but paradoxically, also provided a means to resolve this through reassurance. Women engaged with these interventions flexibly. In contrast to much existing literature, this thesis highlights that while contact with prenatal technologies cemented the reality of the pregnancy for some, they also had the power to add to the ambiguity of participants’ status as a ‘pregnant woman’. In later pregnancy, women’s shifting embodied experiences contributed to a reduction in tentativeness. The ability to feel definite foetal movements, coupled with medical and popular discourses of foetal viability, allowed women to feel less anxious about the safety of the pregnancy and the foetus. As a result, women reported changed interactions with health professionals and advice during the final trimester of pregnancy. This thesis, engaging with literature from sociology, science and technology studies (STS) and anthropology, makes theoretical contributions in three areas. First, its consideration of gestation over time nuances discussions of pregnancy in terms of risk. Second, this research further contributes to literature regarding pregnant embodiment, and conceptualisations of the foetus. Third, the thesis demonstrates that relationships between forms of knowledge mobilised by participants during pregnancy were complex, shifting over the course of gestation, and reflective of women’s experiences of pregnancy as tentative.