Letrozole pregnancy

Has anyone here taken letrozole to get pregnant and ended up pregnant with twins? My dr had said it can increase the chances by 8-10%. I was on letrozole with my first baby but it took 6 months on it before finally getting pregnant. This go around I only took it for 1 round, got pregnant right away, and am sick as a dog (where as my first pregnancy I had it super easy with no sickness). I'm just paranoid I guess and my first appointment isn't until next week