I've been diagnosed with unexplained infertility and have had several stimulated cycles (gonal-f plus HCG trigger), but to no avail. This cycle, multiple follicles (3) were measured a day before the HCG shot was administered to trigger ovulation. At that time, my u/s revealed the following follicle sizes: 11.7, 15.8 and 16mm. Back to back IUI was performed at 24 and 48 hours following the HCG. I am curious what others have experienced with regard to follicle size and successful pregnancy? Singleton, twins, another negative, etc...