Just snooping through - not a mom. But, I tried Nuva Ring for about five months -- the boyfriend couldn't feel it at all. It's super bendy plastic. And if they can feel it, it certainly wouldn't be painful at all. Just a "hmm, oh, hello nuvaring..". It can come out during sex though, in which case you just put it back in.
However : I started getting insane leg cramps in the middle of the night where I'd wake up, jump out of bed, super startled, in a scream/cry from the immediate pain. I'd get it in both legs - and I've NEVER been one to get leg cramps, especially not provoked by exercise. It took me about six weeks before I was watching tv and saw the Nuva Ring commercial that said leg cramps were a big red flag - googled it, and read about the "nuva ring stroke" (
http://www.birthcontrolringlawsuitcenter.com/) and took it out
immediately. I won't
ever try them again.
I, too, have been thinking about Mirena for a long, long time - and as soon as I get the money up that's my route

Maybe do a little more research at least before you cancel that appointment if you're still unsure.