A protective effect has traditionally been attributed to estrogen in psychotic disorders. The aim of this study was to investigate cumulative lifetime estrogen by assessing the menstrual cycle length, age at menarche, and years of difference between the onset of psychotic symptoms and the age of menarche, measuring their effects on symptoms, cognition, social cognition, and metacognition. As it was not possible to directly measure cumulative estrogen levels over the lifetime of a patient, the study sample was composed of 42 women with first-episode psychosis; estrogen levels were inferred by the menstrual cycle length, age at menarche, and years of difference between the onset of psychotic symptoms and menarche. All patients were assessed with a battery of questionnaires using the BDI, PSYRATS, PANSS, STROOP, TAVEC, WSCT, IPSAQ, and BCIS questionnaires. The results related to menstrual cycle length showed a relationship with memory; specifically, shorter cycles with semantic strategies (p = 0.046) and longer cycles with serial strategies in the short term (p = 0.005) as well as in the long term (p = 0.031). The results also showed a relationship with perseverative errors (p = 0.035) and self-certainty (p = 0.049). Only personalized bias (p = 0.030) was found to be significant in relation to the age at menarche. When analyzing the differences in years of difference between the age at menarche and the onset of psychotic symptoms, the results indicated lower scores in women with a smaller difference between both events in memory (short-term (p = 0.050), long-term (p = 0.024), intrusions (p = 0.013), and recognition (p = 0.043)) and non-perseverative errors (p = 0.024). No relationship was found between symptoms and menstrual characteristics. The investigatory outcomes seem to indicate a relationship between estrogen cumulative effects and the memory domain. More in-depth investigations in the field are necessary in order to improve personalized treatment in women with psychosis.