Very sorry for your loss, sending lots of hugs.
I was 19 when I had my miscarriage, we went to the scan and there was no heartbeat. I was in pieces, so I don't know if the midwife didn't mention it or if I just didn't hear, but they put me into a room at the side and gave me a tablet and told me go to back in 2 days if nothing had happened (which it hadn't).
I'm bringing it up because it never occurred to me that I could walk away and wait for it to happen naturally, it's making me think now how it would have been.
I did go back after the 2 days and they put a pessary in at 10am, by 1pm I ran to the toilet because I felt a tiny 'pop' in my belly and everything came away in one go.
It's never a nice thing to go through, but I was grateful I'd had the warning and that it was over and done pretty quickly in a controlled and supervised environment. I'd make the same decision again in the same situation, but I think I'd agree with you if I was actually TTC, let it come away naturally and let your body heal at it's own rate.
If you are in a situation where they are insisting you take the medicated route for your own health, it's quick and painless, at least it was for me, so I hope that can bring you at least some comfort. I remember the 2 days of crying and vomiting in between the two hospital visits, I just wanted to get it over with, the pain of having a baby in there knowing you'll never hear it cry was unbearable. I took the quick and easy option so I could begin the healing process.
I'd found out at my 12 week scan that we'd lost the baby at 9 weeks, so I was at least 3 weeks without anything happening.
It's only your decision, so go with what you feel is best.
I'm very sorry for your loss