Well you could be anywhere between 10 and 14 weeks!
If it helps I had a scan at 7 weeks 3 days and they said only a sac and could not be 7 weeks, more like 4/5 weeks. Rescanned at around 10 weeks, and showed 10 weeks. I knew I had ovulated early so was expecting to be further ahead than dates. When I had my dating scan at 12 weeks, I was measuring 5 days ahead (which tied in with my early ovulation).
So I went from 2 weeks or more behind to 5 days ahead. The reason is two fold, firstly there is a large margin for error in early scans, and the second that if you have a retroverted uterus (common to have) you can measure up to two weeks behind easily. ( see misdiagnosedmiscarriages website)
My guess would be that you are possibly around 12 weeks
Gestational age is based on your LMP, so the 12weeks 3 days on your scan is not what you need to be looking at. You need to look at the other measurements on your scan (which I can't see in the pictures you have posted) normally on the right hand side of the scan. Look for the sac size GS measurement. This will tell you what size they measured and the estimated scan age for that scan. As I say this will not necessarily help, as it can change as it did for me, fairly easily!)
It is possible you are now 14 weeks, as you got the positive test 8 weeks ago, the very earliest that you can test positive would be 3 weeks, so 8+3 means that you could not really be less than 11 weeks. You could well have ovulated late in your cycle.
As for the bloating / filling out, this is a bit of a red herring, as many people have huge bloating early on, but not necessarily.
Sorry but you will have to wait for your next scan to get a better idea of your dates!