Sayang, 8 weeks is still very early, at that stage, sometimes the baby image tak clear lagi even though the sac and yolk sac ada. But please don't worry sendiri, okay? You really need to see your OB or go to the clinic soon , they can check properly, do another scan maybe, and make sure everything progressing like it should. Only the doctor can confirm semua okay from what they see. A few of my mum friends went through the same worry, and turned out fine, tapi kena confirm dengan doctor lah, jangan guess-guess. Hang in there, and get that appointment sorted quickly, yeah?