When my periods re-started (11.5 months after giving birth), I started using a Lunette cup, thanks to all the recs on LJ. Pretty good, except that the little bit on the end you yank it out with sometimes gets into a position where it jabs as I move and OWowOW! Have now trimmed it, which seems to have helped.

Lucky you didn't end up going into Casualty... unless UK doctors are very much more cup-savvy than Australian ones (you can't even buy menstrual cups in Australia - I ordered mine viz NZ), I suspect they wouldn't have had a clue what it was.