It is generally considered safe to have sex during pregnancy, including at 12 weeks. However, there are a few factors to consider. Firstly, if you have a high-risk pregnancy or any complications such as placenta previa or a history of preterm labor, your healthcare provider may advise against intercourse. Additionally, if you or your partner have any sexually transmitted infections (STIs), it is crucial to use protection to prevent transmission to the baby or further complications. It's always best to consult with your healthcare provider for personalized advice based on your specific situation. They can provide guidance and address any concerns you may have about having sex during pregnancy.