Thanks for replies girls. I've decided to go ahead with next cycle as already prescribed - but if it happens again I'll be very annoyed. My clinic says they get maybe 1 of these "cases" a month, and doesn't mean it will happen again with subsequent cycles. My doctors all say that taking higher doses of FSH won't increase the speed of follicle growth -but should grow MORE folli's... I really hope this is the case. Maybe I can ask for an early day 5 or 6 scan just to check there's no misbehaving single follicle!