BACKGROUND: Pregnant women often navigate extensive information from healthcare professionals, social networks and online sources, which can increase anxiety. Understanding their concerns and preferred information sources is crucial for effective antenatal care. OBJECTIVE: To explore worries and information-seeking behaviour among pregnant women in Norway using social media. METHODS: An anonymous, web-based survey was conducted among 1402 pregnant women in Norway from January to March 2022, distributed via Facebook and Instagram. The survey covered 11 pregnancy worries, eight postpartum worries, information sources and thoughts regarding childbirth. RESULTS: Nearly, all participants had concerns, mainly about foetal anomalies (99%, CONCLUSIONS: Pregnancy and postpartum worries are widespread among pregnant women using social media, especially among first-time mothers and those with financial insecurity. Most pregnant women prefer quality-assured websites and healthcare personnel for information. Antenatal care could benefit from offering more tailored information and follow-up, particularly for first-time mothers and financially insecure women.