Aiyoo dear, jangan risau sangat lagi okay. Kantung je nampak at 5 weeks is actually quite normal pa, normally yolk sac baru start nampak around that time, then fetal pole dengan heartbeat datang around 5.5 to 6 weeks. So your doctor is probably just waiting for the next scan to see if baby develops properly.
The bleeding though, I understand lah why you scared. A few of my mum friends experienced some spotting in early weeks and everything turned out fine, but some had more concerning situations. Since you UPT still positive and no more bleeding this morning, that's good sign, but honestly, best is to follow up with your doctor closely, maybe another scan in a week or so to confirm everything is progressing okay. Sometimes dating is just slightly off, sometimes it takes a bit more time to see the fetal pole.
Just take it easy la, avoid heavy lifting, and try not to stress too much (easier said than done, I know!). Fingers crossed for you! But do check with your doc again soon to put your mind at ease, okay?