8 weeks 4 days pregnant... Sac visible but no baby!

Hi guys my name is Samantha Im 20 and about 9 weeks pregnant with my second baby I went for an ultrasound scan today... And I was deverstated to find that there was a healthy blooming sac... But no baby to be seen.... they then done an internal scan I was told that my dates are possibly wrong the sac was measuring only 6 weeks or it's a failing pregnancy (miscarriage) I haven't been offered bloods to check my hormone levels yet For some reason. Can some 1 give me advice as I am in pieces and have to wait a week before my next scan to find out what's going on! I’ve had bleeding & clots since 16th November & had painful cramping for around 2 weeks it’s like mini contractions. I can't help but think the worst right now 😢 me and my Partner are in bits. Any advice is greatfully appreciated thanks.

UPDATE: I had a miscarriage. It was confirmed on the 27/11/17 that we lost our baby at 8 weeks 16/11/17 and baby stopped growing at 6 weeks.