Aiyooo, don't worry too much! 7 weeks is still very early, sometimes the baby blum visible clearly on scan depending on how the pregnancy is dating. Please go see your doctor again soon to confirm everything okay, just to be safe and put your mind at ease. A few of my mum friends went through the same thing and the baby was perfectly fine, just needed another scan a week or two later. Doctor will know best, ya. Take care!