My LMP was 1 December, 2009 - I have 36 day cycles, they have been that long since my miscarriage.

I got a BFP on 4 January, 2010.
I had an ultrasound on 13 January, 2009 and they measured the gestational sac as 5mm (no baby or yolk sac at that stage) and a uterus lining of 1.5cm. My HCG was 5000.

If it is 5mm how far along am I?

Is this going to be a viable pregnancy? I had a miscarriage last July and am very worried that this is too going to be one.

Any advice will be good