The fertilized egg does not clinically cause panic attacks. The fertilized egg is still in the germ cell stage, so it is very, very small and invisible to the naked eye. The fertilized egg is still in the germ cell stage, so it is very small and invisible to the naked eye. Its implantation does not cause any clinical symptoms, so if you have panic attacks, it is best to go to the hospital for the corresponding examination. It is recommended that an electrocardiogram or an ultrasound or both be done to rule out the possibility of organic lesions in the heart, and then a comprehensive analysis can be made. In addition, it is recommended to detect pregnancy by blood HCG at 16-17 days after intercourse. Clinically, if the fertilized egg is laid and the pregnancy continues, the corresponding clinical symptoms will appear, such as gastrointestinal reactions like nausea and vomiting around 45 days.