The transition to motherhood represents a period of challenges and biological, psychological and social changes in women’s lives. This changes can become more challenging in social vulnerability, affecting women’s psychological experience of pregnancy and their well-being. The present study aimed to explore the psychological well-being of pregnant women or mothers in psychosocial vulnerability. This study considered two different temporal moments. 175 pregnant women and mothers of children up to 18 months participated in the study. It was developed in Portugal with the support of an Institution of Social Solidarity that supports maternity on vulnerable conditions. The results of this study showed the existence of associations between self-concept, perceived social support, parental satisfaction, the psychological experience of pregnancy and psychopathological symptoms. A decrease in the perceived social support and in psychopathological symptoms was also identified throughout the study moments.