Empty sack at 12 weeks then something 1 week later?!

[emmagency]

Hi, sorry long post but so weird...
At my first scan around 12 week they discovered an empty sack. We were told to come back in a week's time but being sure of our date there was no doubt for DH and I that this was it.
As if my body had finally got the memo, my preg symptoms disappeared and the spotting that had started days before the scan turned into actual bleeding with all sorts of gross clots.
Like many people (I guess) I had not heard of it before and it was a huge shock. It also 'complexified' feelings about it all and just made it so much more difficult to deal with.

Yesterday was my 2nd scan. I was feeling a bit better by then, just hoping for closure, but then the scan picked up something they hadn't seen/wasn't there last time: certainly no heartbeat but a blob (size of a lentil?) that looks like it's inside the sack (which I was hoping would have start clearing) but could also be outside of it.
It's most likely debris, or the undeveloped foetus that didn't show previously (internal vs external scan last time), but the EPU staff insisted on leaving things be for another 2 weeks before scanning again and then considering options.

We didn't expect an even bigger shock but this definitely was one. Even if we'd conceived right after the missed miscarriage it would show yet so there is nothing to be optimistic about.
My initial worry was passing the miscarriage in the middle of work or the playground (I already have a toddler, she is keeping me from breaking down ❤) but now I am worried about a molar pregnancy!
Anyone got any insights?! The threads I've read about silent miscarriage seem to happen earlier and the remains are either passed or removed, rather than playing tricks!! Thanks