Alah, don't worry lah, 7 weeks is actually still quite early, masa ni memang kantung je yang clear dulu, the fetal pole (the samar-samar janin you saw) usually becomes more visible around 8-9 weeks so gerak gerak je lagi. A few of us in my mum group all had the same experience and by the next scan everything was perfectly fine, heartbeat pun dah terlihat jelas! Tapi memang best check with your doctor pasal timing scan pulak, sebab sometimes dating bisa agak off kalau cycle irregular, so doktor boleh confirm betul-betul weeks berapa you are. Take care ya!