Actually, some of what I've read says that if you ovulate on 50mg of clomid, higher doses might be counteractive and prevent ovulation. So no, a doctor shouldn't give you more than you need to be effective. I can totally understand wanting twins, but it really would be medically irresponsible to try to conceive them (from the doctor's point of view, I mean). The increased risk to both mother and babies is not insignificant, even with twins. Sure, most twins are healthy, and twins do occur naturally, but the risk of serious problems is still much higher for twins than singletons. Good luck!