My partner can feel my IUD

And no; it’s not just the strings... my cervix measured 4 in and a little bit and his penis is over 5 in for sure. When he penetrates deeply it hurts, even before the IUD. So today I randomly asked if he feels the strings and he said not only the strings, but my IUD a little too. I said there’s no way. He said “well I feel like something solid, small, like metal” (that’s my IUD). Now I just went to the Dr to get a pelvic exam and to make sure the IUD was in place and it is... we had sex before the check up so it hasn’t moved as him and I have felt this before. Has anyone ever experienced this? My concern is what if he pushes it a bit every time and that becomes an issue (like gets out of place, embedded, or doesn’t prevent pregnancy).