The "postpartum blues" is a mild, predictable mood disturbance occurring within the first several days following childbirth. Previous analyses of the "blues" symptom structure yielded inconclusive findings, making reliable assessment a significant methodological limitation. The current study aimed to explicate the symptom structure of women's mood following childbirth, and to examine psychometric properties of the Daily Experiences Questionnaire (DEQ), an adapted version of the Kennerley Blues Questionnaire that included additional items from the Positive and Negative Affect Schedule. Mothers who recently delivered (N = 216) were recruited from a university hospital and asked to complete mood ratings on six consecutive days using the DEQ. Exploratory factor analysis yielded an interpretable two-factor solution identified as Negative Affect and Positive Affect. Scale reliability indices were excellent, with a high level of agreement in factor structure over time. This two-factor model provides reliable assessment of women's mood in the early postpartum, informing the study of reproductive-related mood disorders.