So sorry you're going through this.
My experience was pretty much exactly the same. Baby didn't develop past about 5 weeks, found out on scan at 7 weeks. I preferred a natural mc to any intervention, so waited a further 3+ weeks and nothing happened. A tiny bit of spotting here and there, but I had more bleeding than that in my healthy straightforward pregnancies. It just never happened. Finally by 11 weeks, I decided that I did want intervention because I'd spent 3 weeks waiting for it to happen and not being able to travel for work (did a lot of travel, but was afraid to start mc alone away from home).
I saw a very lovely specialist midwife at the EPU who talked to me about medical and surgical management. I didn't want an operation, but she said that if she was ever in my shoes, she would never opt for the medical management as it can be really traumatic and awful. I decided on surgical. They booked me in for 2 days later. It was as easy as it possibly could be. The day surgery staff were lovely and sensitive and really supportive, and it was all fine. I'm very glad that's the route it all went in the end, if I had to be in that position as it was very easy and I hardly felt any discomfort. (I was pregnant about 6 weeks after the d&c and have a nearly 2 year old now, so all worked out in the end, even though it was awful at the time).
The hospital will need to do 2 scans, at least 1 week apart and will need to be sure that baby is not developing. In my case, they did an analysis of blood flow or something like that via ultrasound, which showed that there was no activity and no further development was possible. If there is any doubt, they will not let you proceed with intervention, so if they are saying no further scans then it's because they are sure. It's hard to come to terms with, but it's much easier when you are no longer stuck in limbo. If you need further reassurance, would you consider a private scan? I had one with mine as well (that was my first scan at 7 weeks) and it was well worth the money to know what was going on.