4wks + 3 days and no gestational sac

Help!!!! I'm 4 weeks and 3 days today. I beta drawn was on 7/26 and was 156, second beta drawn on 7/28 and was 414, third beta drawn today and is 1459. First ultrasound done today and gestational sac found. Nothing intrauterine or ectopic. My RE says too early but the ER doc says possible blighted ovum. I'm scared to death that this baby might not make. Not sure where the baby is located but definitely something there because my levels are increasing. Anyone ever have this happen and have a healthy pregnancy and baby.