Aih, kantung kosong di 7 minggu memang biasa jadi worry lah, tapi honestly ada peluang juga baby ada, sometimes dating bukan tepat, or baby just belum visible lagi. Yang penting tu is when you go for follow-up ultrasound, usually around 9-10 minggu baru clear whether ada baby or blighted ovum, kalau memang kantung terus membesar and fetal pole appear, bagus lah. Tapi ada juga yang unfortunately kantung ja without development, so it's a wait-and-see situation. Best thing is to follow up with your specialist as planned and trust the scan progression, stress tak membantu pun, so try to stay calm and let the doctor guide you from the next scan onwards.