I recently went in to determine a due date. The ultrasound technician was very short with me and incredibly rude (it didn't help that my 9mo daughter was ready for a nap, and wanted mommy to hold her) I apparently had not filled my bladder enough for an abdominal ultrasound, and so we went ahead with the vaginal. She determined I was 8 wks and 5 days. She also found a second sac, it was sitting just above the other. She said it was just an extra sac that never developed/ absorbed twin and that it would resolve itself. However, now when I look at the sonograph I keep thinking the little stinker was just hiding behind Twin#1. Is this possible? They didn't check my blood or urine that day (so a hightened HCG is undetermined) and I have a tipped/retroverted/tilted (whichever you prefer) uterus. At a "looking up" angle is it possible the entire second sac was not fully visible?