It's more likely that it didn't have anything to do with the ring- it's really easy for the vaginal walls or the labia to get scratched or something during foreplay or sex. The ring is so pliable and smooth, it just doesn't seem likely that it made you bleed! But I guess anything is possible.
When I used the ring, after about 10 months of using it, after sex I would feel really irritated, like his penis had been wrapped in sandpaper. I never had any bleeding, though. But I know it wasn't a lubrication issue, because we use lube quite often. The doc said it couldn't have been the ring but I swear it was because as soon as I got off it the irritation went away.
Unfortunately, that was the only side effect I had from it, and I miss it