I have DCDA twin uterine pregnancy one fetus is develop at 141bpm at 7 weeks 2 weeks and no embryo was seen in sac b and today i had a follow up scan in which same sac a fetus was developing with 175bpm but still sac b did not have embryo or fetal pole but the size of gestation sac is increasing so does it means i can still hope that sac B will grow or appear in next ultrasound around 12 weeks or else what will happen?