Background We hypothesised that experiencing ambivalence toward the childbearing goal would be related to indicators of well‐being, stress, and coping among women with planned pregnancies. Methods Study 1 (N = 208) tested cross‐sectional associations between goal ambivalence and measures of well‐being, stress, and coping. It also included a postpartum measurement point (N = 71) to examine prospective effects of goal ambivalence. Study 2 (N = 109) extended the investigation to within‐person effects in a three‐week daily diary assessment. Results In Study 1, goal ambivalence in pregnant women was positively associated with depressive symptoms, perceived stress, and pregnancy‐specific avoidance‐oriented coping, and negatively associated with coping self‐efficacy. Goal ambivalence also predicted changes in life satisfaction, depressive symptoms, perceived stress, and coping self‐efficacy postpartum. Study 2 revealed within‐person effects of daily fluctuations in goal ambivalence on day‐to‐day changes in positive emotions, negative activation, and avoidance‐oriented coping. Conclusions Ambivalence towards the childbearing goal is a source of significant distress to pregnant women with planned pregnancies and its effects seem to extend into the postpartum period. These findings may have important clinical implications for maternal and child well‐being. Future studies should examine whether goal ambivalence during pregnancy affects the maternal–child relationship in the long term.